diff --git a/api/build.gradle b/api/build.gradle
index ebaca4c87..001d25791 100644
--- a/api/build.gradle
+++ b/api/build.gradle
@@ -28,12 +28,12 @@ jacocoTestReport {
 }
 
 dependencies {
-    implementation 'org.jsoup:jsoup:1.10.3'
-    implementation 'org.apache.commons:commons-lang3:3.7'
-    implementation 'com.google.code.gson:gson:2.8.2'
+    implementation "org.jsoup:jsoup:$jsoup"
+    implementation "org.apache.commons:commons-lang3:$apacheLang"
+    implementation "com.google.code.gson:gson:$gson"
 
-    testImplementation 'junit:junit:4.12'
-    testImplementation 'org.mockito:mockito-core:2.13.0'
+    testImplementation "junit:junit:$junit"
+    testImplementation "org.mockito:mockito-core:$mockito"
 }
 
 version = PUBLISH_VERSION
diff --git a/app/build.gradle b/app/build.gradle
index 055fb302c..6b63b2d35 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -21,13 +21,13 @@ apply from: '../jacoco.gradle'
 apply from: '../android-sonarqube.gradle'
 
 android {
-    compileSdkVersion 27
-    buildToolsVersion "27.0.3"
+    compileSdkVersion 26
+    buildToolsVersion "26.0.3"
     defaultConfig {
         applicationId "io.github.wulkanowy"
         testApplicationId "io.github.tests.wulkanowy"
         minSdkVersion 15
-        targetSdkVersion 27
+        targetSdkVersion 26
         versionCode 4
         versionName "0.2.1"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
@@ -68,42 +68,39 @@ greendao {
 
 dependencies {
     implementation project(':api')
-    implementation 'com.android.support:appcompat-v7:27.1.0'
-    implementation 'com.android.support:design:27.1.0'
-    implementation 'com.android.support:support-v4:27.1.0'
-    implementation 'com.android.support:recyclerview-v7:27.1.0'
-    implementation 'com.android.support:cardview-v7:27.1.0'
-    implementation 'com.android.support:customtabs:27.1.0'
-    implementation 'com.firebase:firebase-jobdispatcher:0.8.5'
-    implementation 'org.apache.commons:commons-lang3:3.7'
-    implementation 'eu.davidea:flexible-adapter:5.0.0-rc4'
-    implementation 'eu.davidea:flexible-adapter-ui:1.0.0-b1'
-    implementation 'org.apache.commons:commons-collections4:4.1'
-    implementation 'org.greenrobot:greendao:3.2.2'
-    implementation 'com.github.yuweiguocn:GreenDaoUpgradeHelper:v2.0.2'
-    implementation 'com.jakewharton:butterknife:8.8.1'
-    implementation 'joda-time:joda-time:2.9.9'
-    implementation 'com.google.dagger:dagger-android:2.14.1'
-    implementation 'com.google.dagger:dagger-android-support:2.14.1'
-    implementation 'com.aurelhubert:ahbottomnavigation:2.1.0'
+    implementation "com.android.support:support-v4:$supportVersion"
+    implementation "com.android.support:design:$supportVersion"
+    implementation "com.android.support:cardview-v7:$supportVersion"
+    implementation "com.android.support:customtabs:$supportVersion"
+    implementation "com.firebase:firebase-jobdispatcher:$firebaseJob"
+    implementation "org.apache.commons:commons-lang3:$apacheLang"
+    implementation "org.apache.commons:commons-collections4:$apacheCollections"
+    implementation "eu.davidea:flexible-adapter:$flexibleAdapter"
+    implementation "eu.davidea:flexible-adapter-ui:$flexibleUi"
+    implementation "org.greenrobot:greendao:$greenDao"
+    implementation "com.github.yuweiguocn:GreenDaoUpgradeHelper:$greenDaoHelper"
+    implementation "com.jakewharton:butterknife:$butterknife"
+    implementation "joda-time:joda-time:$jodaTime"
+    implementation "com.google.dagger:dagger-android-support:$dagger2"
+    implementation "com.aurelhubert:ahbottomnavigation:$ahbottom"
 
-    implementation('com.crashlytics.sdk.android:crashlytics:2.8.0@aar') {
+    implementation("com.crashlytics.sdk.android:crashlytics:$crashlyticsSdk@aar") {
         transitive = true
     }
-    implementation('com.crashlytics.sdk.android:answers:1.4.1@aar') {
+    implementation("com.crashlytics.sdk.android:answers:$crashlyticsAnswers@aar") {
         transitive = true
     }
 
-    annotationProcessor 'com.google.dagger:dagger-android-processor:2.14.1'
-    annotationProcessor 'com.google.dagger:dagger-compiler:2.14.1'
-    annotationProcessor 'com.jakewharton:butterknife-compiler:8.8.1'
+    annotationProcessor "com.google.dagger:dagger-android-processor:$dagger2"
+    annotationProcessor "com.google.dagger:dagger-compiler:$dagger2"
+    annotationProcessor "com.jakewharton:butterknife-compiler:$butterknife"
 
-    debugImplementation 'com.amitshekhar.android:debug-db:1.0.1'
-    debugImplementation 'net.zetetic:android-database-sqlcipher:3.5.9'
+    debugImplementation "com.amitshekhar.android:debug-db:$debugDb"
+    debugImplementation "net.zetetic:android-database-sqlcipher:$sqlcipher"
 
-    testImplementation 'junit:junit:4.12'
-    testImplementation 'org.mockito:mockito-core:2.13.0'
+    testImplementation "junit:junit:$junit"
+    testImplementation "org.mockito:mockito-core:$mockito"
 
-    androidTestImplementation 'com.android.support.test:runner:1.0.1'
-    androidTestImplementation 'org.mockito:mockito-android:2.13.0'
+    androidTestImplementation "com.android.support.test:runner:$testRunner"
+    androidTestImplementation "org.mockito:mockito-android:$mockito"
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceContract.java b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceContract.java
index f8d3b3025..545e300ea 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceContract.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceContract.java
@@ -17,20 +17,16 @@ public interface AttendanceContract {
 
         void setAdapterWithTabLayout();
 
-        void setChildFragmentSelected(int position, boolean selected);
-
         boolean isMenuVisible();
     }
 
     @PerActivity
     interface Presenter extends BaseContract.Presenter<View> {
 
-        void onFragmentVisible(boolean isVisible);
-
-        void onTabSelected(int position);
-
-        void onTabUnselected(int position);
+        void onFragmentActivated(boolean isVisible);
 
         void onStart(View view, OnFragmentIsReadyListener listener);
+
+        void setRestoredPosition(int position);
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceFragment.java b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceFragment.java
index 82bb2520b..4dd179b15 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceFragment.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceFragment.java
@@ -20,7 +20,9 @@ import io.github.wulkanowy.ui.base.BaseFragment;
 import io.github.wulkanowy.ui.main.OnFragmentIsReadyListener;
 import io.github.wulkanowy.ui.main.TabsData;
 
-public class AttendanceFragment extends BaseFragment implements AttendanceContract.View, TabLayout.OnTabSelectedListener {
+public class AttendanceFragment extends BaseFragment implements AttendanceContract.View {
+
+    private static final String CURRENT_ITEM_KEY = "CurrentItem";
 
     @BindView(R.id.attendance_fragment_viewpager)
     ViewPager viewPager;
@@ -45,6 +47,10 @@ public class AttendanceFragment extends BaseFragment implements AttendanceContra
             component.inject(this);
             setButterKnife(ButterKnife.bind(this, view));
             presenter.onStart(this, (OnFragmentIsReadyListener) getActivity());
+
+            if (savedInstanceState != null) {
+                presenter.setRestoredPosition(savedInstanceState.getInt(CURRENT_ITEM_KEY));
+            }
         }
 
         return view;
@@ -54,25 +60,10 @@ public class AttendanceFragment extends BaseFragment implements AttendanceContra
     public void setMenuVisibility(boolean menuVisible) {
         super.setMenuVisibility(menuVisible);
         if (presenter != null) {
-            presenter.onFragmentVisible(menuVisible);
+            presenter.onFragmentActivated(menuVisible);
         }
     }
 
-    @Override
-    public void onTabSelected(TabLayout.Tab tab) {
-        presenter.onTabSelected(tab.getPosition());
-    }
-
-    @Override
-    public void onTabUnselected(TabLayout.Tab tab) {
-        presenter.onTabUnselected(tab.getPosition());
-    }
-
-    @Override
-    public void onTabReselected(TabLayout.Tab tab) {
-        //do nothing
-    }
-
     @Override
     public void setTabDataToAdapter(TabsData tabsData) {
         pagerAdapter.setTabsData(tabsData);
@@ -81,14 +72,7 @@ public class AttendanceFragment extends BaseFragment implements AttendanceContra
     @Override
     public void setAdapterWithTabLayout() {
         viewPager.setAdapter(pagerAdapter);
-
         tabLayout.setupWithViewPager(viewPager);
-        tabLayout.addOnTabSelectedListener(this);
-    }
-
-    @Override
-    public void setChildFragmentSelected(int position, boolean selected) {
-        ((AttendanceTabFragment) pagerAdapter.getItem(position)).setSelected(selected);
     }
 
     @Override
@@ -109,6 +93,12 @@ public class AttendanceFragment extends BaseFragment implements AttendanceContra
         }
     }
 
+    @Override
+    public void onSaveInstanceState(Bundle outState) {
+        outState.putInt(CURRENT_ITEM_KEY, viewPager.getCurrentItem());
+        super.onSaveInstanceState(outState);
+    }
+
     @Override
     public void onDestroyView() {
         presenter.onDestroy();
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceHeaderItem.java b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceHeaderItem.java
index 306065eea..a055156d6 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceHeaderItem.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceHeaderItem.java
@@ -19,6 +19,7 @@ import butterknife.BindView;
 import butterknife.ButterKnife;
 import eu.davidea.flexibleadapter.FlexibleAdapter;
 import eu.davidea.flexibleadapter.items.AbstractExpandableHeaderItem;
+import eu.davidea.flexibleadapter.items.IFlexible;
 import eu.davidea.viewholders.ExpandableViewHolder;
 import io.github.wulkanowy.R;
 import io.github.wulkanowy.data.db.dao.entities.Day;
@@ -58,12 +59,13 @@ public class AttendanceHeaderItem
     }
 
     @Override
-    public HeaderViewHolder createViewHolder(View view, FlexibleAdapter adapter) {
+    public HeaderViewHolder createViewHolder(View view, FlexibleAdapter<IFlexible> adapter) {
         return new HeaderViewHolder(view, adapter);
     }
 
     @Override
-    public void bindViewHolder(FlexibleAdapter adapter, HeaderViewHolder holder, int position, List payloads) {
+    public void bindViewHolder(FlexibleAdapter<IFlexible> adapter, HeaderViewHolder holder,
+                               int position, List<Object> payloads) {
         holder.onBind(day, getSubItems());
     }
 
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendancePresenter.java b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendancePresenter.java
index 73dd44ca7..bad68e166 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendancePresenter.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendancePresenter.java
@@ -24,7 +24,7 @@ public class AttendancePresenter extends BasePresenter<AttendanceContract.View>
 
     private OnFragmentIsReadyListener listener;
 
-    private int positionToScroll;
+    private int positionToScroll = 0;
 
     private boolean isFirstSight = false;
 
@@ -45,7 +45,10 @@ public class AttendancePresenter extends BasePresenter<AttendanceContract.View>
         if (dates.isEmpty()) {
             dates = TimeUtils.getMondaysFromCurrentSchoolYear();
         }
-        positionToScroll = dates.indexOf(TimeUtils.getDateOfCurrentMonday(true));
+
+        if (positionToScroll == 0) {
+            positionToScroll = dates.indexOf(TimeUtils.getDateOfCurrentMonday(true));
+        }
 
         if (!isFirstSight) {
             isFirstSight = true;
@@ -57,22 +60,12 @@ public class AttendancePresenter extends BasePresenter<AttendanceContract.View>
     }
 
     @Override
-    public void onFragmentVisible(boolean isVisible) {
+    public void onFragmentActivated(boolean isVisible) {
         if (isVisible) {
             getView().setActivityTitle();
         }
     }
 
-    @Override
-    public void onTabSelected(int position) {
-        getView().setChildFragmentSelected(position, true);
-    }
-
-    @Override
-    public void onTabUnselected(int position) {
-        getView().setChildFragmentSelected(position, false);
-    }
-
     @Override
     public void onDoInBackgroundLoading() throws Exception {
         for (String date : dates) {
@@ -97,6 +90,11 @@ public class AttendancePresenter extends BasePresenter<AttendanceContract.View>
         }
     }
 
+    @Override
+    public void setRestoredPosition(int position) {
+        this.positionToScroll = position;
+    }
+
     @Override
     public void onDestroy() {
         isFirstSight = false;
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceSubItem.java b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceSubItem.java
index 6da35555a..8249a5139 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceSubItem.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceSubItem.java
@@ -16,6 +16,7 @@ import butterknife.BindView;
 import butterknife.ButterKnife;
 import eu.davidea.flexibleadapter.FlexibleAdapter;
 import eu.davidea.flexibleadapter.items.AbstractSectionableItem;
+import eu.davidea.flexibleadapter.items.IFlexible;
 import eu.davidea.viewholders.FlexibleViewHolder;
 import io.github.wulkanowy.R;
 import io.github.wulkanowy.data.db.dao.entities.AttendanceLesson;
@@ -60,12 +61,13 @@ class AttendanceSubItem
     }
 
     @Override
-    public AttendanceSubItem.SubItemViewHolder createViewHolder(View view, FlexibleAdapter adapter) {
-        return new AttendanceSubItem.SubItemViewHolder(view, adapter);
+    public SubItemViewHolder createViewHolder(View view, FlexibleAdapter<IFlexible> adapter) {
+        return new SubItemViewHolder(view, adapter);
     }
 
     @Override
-    public void bindViewHolder(FlexibleAdapter adapter, AttendanceSubItem.SubItemViewHolder holder, int position, List payloads) {
+    public void bindViewHolder(FlexibleAdapter<IFlexible> adapter, SubItemViewHolder holder,
+                               int position, List<Object> payloads) {
         holder.onBind(lesson);
     }
 
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceTabContract.java b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceTabContract.java
index 1bac005d6..dcb16bf88 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceTabContract.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceTabContract.java
@@ -21,12 +21,10 @@ public interface AttendanceTabContract {
 
     interface Presenter extends BaseContract.Presenter<AttendanceTabContract.View> {
 
-        void onFragmentSelected(boolean isSelected);
+        void onFragmentActivated(boolean isSelected);
 
         void setArgumentDate(String date);
 
-        void onStart(AttendanceTabContract.View view, boolean isPrimary);
-
         void onRefresh();
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceTabFragment.java b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceTabFragment.java
index 90313daa6..b635da2b3 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceTabFragment.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceTabFragment.java
@@ -27,12 +27,6 @@ public class AttendanceTabFragment extends BaseFragment implements AttendanceTab
 
     private static final String ARGUMENT_KEY = "date";
 
-    private static final String SAVED_KEY = "isSelected";
-
-    private boolean isPrimary = false;
-
-    private boolean isSelected = false;
-
     @BindView(R.id.attendance_tab_fragment_recycler)
     RecyclerView recyclerView;
 
@@ -51,6 +45,8 @@ public class AttendanceTabFragment extends BaseFragment implements AttendanceTab
     @Inject
     FlexibleAdapter<AttendanceHeaderItem> adapter;
 
+    private boolean isFragmentVisible = false;
+
     public static AttendanceTabFragment newInstance(String date) {
         AttendanceTabFragment fragmentTab = new AttendanceTabFragment();
 
@@ -61,15 +57,6 @@ public class AttendanceTabFragment extends BaseFragment implements AttendanceTab
         return fragmentTab;
     }
 
-    @Override
-    public void onCreate(@Nullable Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-
-        if (savedInstanceState != null) {
-            isSelected = savedInstanceState.getBoolean(SAVED_KEY, isSelected);
-        }
-    }
-
     @Nullable
     @Override
     public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
@@ -84,7 +71,8 @@ public class AttendanceTabFragment extends BaseFragment implements AttendanceTab
                 presenter.setArgumentDate(getArguments().getString(ARGUMENT_KEY));
             }
 
-            presenter.onStart(this, isPrimary);
+            presenter.onStart(this);
+            presenter.onFragmentActivated(isFragmentVisible);
         }
         return view;
     }
@@ -111,10 +99,9 @@ public class AttendanceTabFragment extends BaseFragment implements AttendanceTab
     @Override
     public void setMenuVisibility(boolean menuVisible) {
         super.setMenuVisibility(menuVisible);
-        if (presenter != null && getView() != null) {
-            presenter.onFragmentSelected(isSelected);
-        } else if (isSelected) {
-            isPrimary = true;
+        isFragmentVisible = menuVisible;
+        if (presenter != null) {
+            presenter.onFragmentActivated(menuVisible);
         }
     }
 
@@ -143,10 +130,6 @@ public class AttendanceTabFragment extends BaseFragment implements AttendanceTab
         noItemView.setVisibility(show ? View.VISIBLE : View.INVISIBLE);
     }
 
-    public void setSelected(boolean selected) {
-        isSelected = selected;
-    }
-
     @Override
     public void onError(String message) {
         if (getActivity() != null) {
@@ -155,15 +138,8 @@ public class AttendanceTabFragment extends BaseFragment implements AttendanceTab
         }
     }
 
-    @Override
-    public void onSaveInstanceState(@NonNull Bundle outState) {
-        outState.putBoolean(SAVED_KEY, isSelected);
-        super.onSaveInstanceState(outState);
-    }
-
     @Override
     public void onDestroyView() {
-        isPrimary = false;
         presenter.onDestroy();
         super.onDestroyView();
     }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceTabPresenter.java b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceTabPresenter.java
index 48aff81c0..1db29cb1e 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceTabPresenter.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceTabPresenter.java
@@ -33,21 +33,22 @@ public class AttendanceTabPresenter extends BasePresenter<AttendanceTabContract.
     }
 
     @Override
-    public void onStart(AttendanceTabContract.View view, boolean isPrimary) {
+    public void onStart(AttendanceTabContract.View view) {
         super.onStart(view);
         getView().showProgressBar(true);
         getView().showNoItem(false);
-        onFragmentSelected(isPrimary);
     }
 
     @Override
-    public void onFragmentSelected(boolean isSelected) {
-        if (!isFirstSight && isSelected) {
+    public void onFragmentActivated(boolean isSelected) {
+        if (!isFirstSight && isSelected && isViewAttached()) {
             isFirstSight = true;
 
             loadingTask = new AbstractTask();
             loadingTask.setOnFirstLoadingListener(this);
             loadingTask.execute();
+        } else if (!isSelected) {
+            cancelAsyncTasks();
         }
     }
 
@@ -157,10 +158,7 @@ public class AttendanceTabPresenter extends BasePresenter<AttendanceTabContract.
         getRepository().syncAttendance(date);
     }
 
-    @Override
-    public void onDestroy() {
-        isFirstSight = false;
-
+    private void cancelAsyncTasks() {
         if (refreshTask != null) {
             refreshTask.cancel(true);
             refreshTask = null;
@@ -169,6 +167,12 @@ public class AttendanceTabPresenter extends BasePresenter<AttendanceTabContract.
             loadingTask.cancel(true);
             loadingTask = null;
         }
+    }
+
+    @Override
+    public void onDestroy() {
+        cancelAsyncTasks();
+        isFirstSight = false;
         super.onDestroy();
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableContract.java b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableContract.java
index eaad05056..aa4576bf4 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableContract.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableContract.java
@@ -17,20 +17,16 @@ public interface TimetableContract {
 
         void setAdapterWithTabLayout();
 
-        void setChildFragmentSelected(int position, boolean selected);
-
         boolean isMenuVisible();
     }
 
     @PerActivity
     interface Presenter extends BaseContract.Presenter<View> {
 
-        void onFragmentVisible(boolean isVisible);
-
-        void onTabSelected(int position);
-
-        void onTabUnselected(int position);
+        void onFragmentActivated(boolean isVisible);
 
         void onStart(View view, OnFragmentIsReadyListener listener);
+
+        void setRestoredPosition(int position);
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableFragment.java b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableFragment.java
index 8bef4fb22..2df28df2c 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableFragment.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableFragment.java
@@ -20,7 +20,9 @@ import io.github.wulkanowy.ui.base.BaseFragment;
 import io.github.wulkanowy.ui.main.OnFragmentIsReadyListener;
 import io.github.wulkanowy.ui.main.TabsData;
 
-public class TimetableFragment extends BaseFragment implements TimetableContract.View, TabLayout.OnTabSelectedListener {
+public class TimetableFragment extends BaseFragment implements TimetableContract.View {
+
+    private static final String CURRENT_ITEM_KEY = "CurrentItem";
 
     @BindView(R.id.timetable_fragment_viewpager)
     ViewPager viewPager;
@@ -44,6 +46,10 @@ public class TimetableFragment extends BaseFragment implements TimetableContract
             component.inject(this);
             setButterKnife(ButterKnife.bind(this, view));
             presenter.onStart(this, (OnFragmentIsReadyListener) getActivity());
+
+            if (savedInstanceState != null) {
+                presenter.setRestoredPosition(savedInstanceState.getInt(CURRENT_ITEM_KEY));
+            }
         }
         return view;
     }
@@ -52,25 +58,10 @@ public class TimetableFragment extends BaseFragment implements TimetableContract
     public void setMenuVisibility(boolean menuVisible) {
         super.setMenuVisibility(menuVisible);
         if (presenter != null) {
-            presenter.onFragmentVisible(menuVisible);
+            presenter.onFragmentActivated(menuVisible);
         }
     }
 
-    @Override
-    public void onTabSelected(TabLayout.Tab tab) {
-        presenter.onTabSelected(tab.getPosition());
-    }
-
-    @Override
-    public void onTabUnselected(TabLayout.Tab tab) {
-        presenter.onTabUnselected(tab.getPosition());
-    }
-
-    @Override
-    public void onTabReselected(TabLayout.Tab tab) {
-        //do nothing
-    }
-
     @Override
     public void setTabDataToAdapter(TabsData tabsData) {
         pagerAdapter.setTabsData(tabsData);
@@ -79,14 +70,7 @@ public class TimetableFragment extends BaseFragment implements TimetableContract
     @Override
     public void setAdapterWithTabLayout() {
         viewPager.setAdapter(pagerAdapter);
-
         tabLayout.setupWithViewPager(viewPager);
-        tabLayout.addOnTabSelectedListener(this);
-    }
-
-    @Override
-    public void setChildFragmentSelected(int position, boolean selected) {
-        ((TimetableTabFragment) pagerAdapter.getItem(position)).setSelected(selected);
     }
 
     @Override
@@ -107,6 +91,12 @@ public class TimetableFragment extends BaseFragment implements TimetableContract
         }
     }
 
+    @Override
+    public void onSaveInstanceState(Bundle outState) {
+        outState.putInt(CURRENT_ITEM_KEY, viewPager.getCurrentItem());
+        super.onSaveInstanceState(outState);
+    }
+
     @Override
     public void onDestroyView() {
         presenter.onDestroy();
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableHeaderItem.java b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableHeaderItem.java
index d704e8a3a..c904d9317 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableHeaderItem.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableHeaderItem.java
@@ -19,6 +19,7 @@ import butterknife.BindView;
 import butterknife.ButterKnife;
 import eu.davidea.flexibleadapter.FlexibleAdapter;
 import eu.davidea.flexibleadapter.items.AbstractExpandableHeaderItem;
+import eu.davidea.flexibleadapter.items.IFlexible;
 import eu.davidea.viewholders.ExpandableViewHolder;
 import io.github.wulkanowy.R;
 import io.github.wulkanowy.data.db.dao.entities.Day;
@@ -58,12 +59,13 @@ public class TimetableHeaderItem
     }
 
     @Override
-    public HeaderViewHolder createViewHolder(View view, FlexibleAdapter adapter) {
+    public HeaderViewHolder createViewHolder(View view, FlexibleAdapter<IFlexible> adapter) {
         return new HeaderViewHolder(view, adapter);
     }
 
     @Override
-    public void bindViewHolder(FlexibleAdapter adapter, HeaderViewHolder holder, int position, List payloads) {
+    public void bindViewHolder(FlexibleAdapter<IFlexible> adapter, HeaderViewHolder holder,
+                               int position, List<Object> payloads) {
         holder.onBind(day, getSubItems());
     }
 
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetablePresenter.java b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetablePresenter.java
index e816a1907..080ec90ba 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetablePresenter.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetablePresenter.java
@@ -24,7 +24,7 @@ public class TimetablePresenter extends BasePresenter<TimetableContract.View>
 
     private OnFragmentIsReadyListener listener;
 
-    private int positionToScroll;
+    private int positionToScroll = 0;
 
     private boolean isFirstSight = false;
 
@@ -45,7 +45,10 @@ public class TimetablePresenter extends BasePresenter<TimetableContract.View>
         if (dates.isEmpty()) {
             dates = TimeUtils.getMondaysFromCurrentSchoolYear();
         }
-        positionToScroll = dates.indexOf(TimeUtils.getDateOfCurrentMonday(true));
+
+        if (positionToScroll == 0) {
+            positionToScroll = dates.indexOf(TimeUtils.getDateOfCurrentMonday(true));
+        }
 
         if (!isFirstSight) {
             isFirstSight = true;
@@ -57,22 +60,12 @@ public class TimetablePresenter extends BasePresenter<TimetableContract.View>
     }
 
     @Override
-    public void onFragmentVisible(boolean isVisible) {
+    public void onFragmentActivated(boolean isVisible) {
         if (isVisible) {
             getView().setActivityTitle();
         }
     }
 
-    @Override
-    public void onTabSelected(int position) {
-        getView().setChildFragmentSelected(position, true);
-    }
-
-    @Override
-    public void onTabUnselected(int position) {
-        getView().setChildFragmentSelected(position, false);
-    }
-
     @Override
     public void onDoInBackgroundLoading() throws Exception {
         for (String date : dates) {
@@ -84,7 +77,6 @@ public class TimetablePresenter extends BasePresenter<TimetableContract.View>
     @Override
     public void onCanceledLoadingAsync() {
         //do nothing
-
     }
 
     @Override
@@ -97,6 +89,11 @@ public class TimetablePresenter extends BasePresenter<TimetableContract.View>
         }
     }
 
+    @Override
+    public void setRestoredPosition(int position) {
+        this.positionToScroll = position;
+    }
+
     @Override
     public void onDestroy() {
         isFirstSight = false;
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableSubItem.java b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableSubItem.java
index ca82f783f..3d85772a6 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableSubItem.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableSubItem.java
@@ -17,6 +17,7 @@ import butterknife.BindView;
 import butterknife.ButterKnife;
 import eu.davidea.flexibleadapter.FlexibleAdapter;
 import eu.davidea.flexibleadapter.items.AbstractSectionableItem;
+import eu.davidea.flexibleadapter.items.IFlexible;
 import eu.davidea.viewholders.FlexibleViewHolder;
 import io.github.wulkanowy.R;
 import io.github.wulkanowy.data.db.dao.entities.TimetableLesson;
@@ -27,7 +28,7 @@ public class TimetableSubItem
 
     private TimetableLesson lesson;
 
-    public TimetableSubItem(TimetableHeaderItem header, TimetableLesson lesson) {
+    TimetableSubItem(TimetableHeaderItem header, TimetableLesson lesson) {
         super(header);
         this.lesson = lesson;
     }
@@ -62,12 +63,13 @@ public class TimetableSubItem
     }
 
     @Override
-    public SubItemViewHolder createViewHolder(View view, FlexibleAdapter adapter) {
+    public SubItemViewHolder createViewHolder(View view, FlexibleAdapter<IFlexible> adapter) {
         return new SubItemViewHolder(view, adapter);
     }
 
     @Override
-    public void bindViewHolder(FlexibleAdapter adapter, SubItemViewHolder holder, int position, List payloads) {
+    public void bindViewHolder(FlexibleAdapter<IFlexible> adapter, SubItemViewHolder holder,
+                               int position, List<Object> payloads) {
         holder.onBind(lesson);
     }
 
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableTabContract.java b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableTabContract.java
index d17e6e557..0d6bdf2a6 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableTabContract.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableTabContract.java
@@ -23,12 +23,10 @@ public interface TimetableTabContract {
 
     interface Presenter extends BaseContract.Presenter<View> {
 
-        void onFragmentSelected(boolean isSelected);
+        void onFragmentActivated(boolean isSelected);
 
         void setArgumentDate(String date);
 
-        void onStart(View view, boolean isPrimary);
-
         void onRefresh();
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableTabFragment.java b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableTabFragment.java
index 65841247d..9cbca0452 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableTabFragment.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableTabFragment.java
@@ -28,12 +28,6 @@ public class TimetableTabFragment extends BaseFragment implements TimetableTabCo
 
     private static final String ARGUMENT_KEY = "date";
 
-    private static final String SAVED_KEY = "isSelected";
-
-    private boolean isPrimary = false;
-
-    private boolean isSelected = false;
-
     @BindView(R.id.timetable_tab_fragment_recycler)
     RecyclerView recyclerView;
 
@@ -55,6 +49,8 @@ public class TimetableTabFragment extends BaseFragment implements TimetableTabCo
     @Inject
     FlexibleAdapter<TimetableHeaderItem> adapter;
 
+    private boolean isFragmentVisible = false;
+
     public static TimetableTabFragment newInstance(String date) {
         TimetableTabFragment fragmentTab = new TimetableTabFragment();
 
@@ -65,14 +61,6 @@ public class TimetableTabFragment extends BaseFragment implements TimetableTabCo
         return fragmentTab;
     }
 
-    @Override
-    public void onCreate(@Nullable Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        if (savedInstanceState != null) {
-            isSelected = savedInstanceState.getBoolean(SAVED_KEY, isSelected);
-        }
-    }
-
     @Nullable
     @Override
     public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
@@ -86,8 +74,8 @@ public class TimetableTabFragment extends BaseFragment implements TimetableTabCo
             if (getArguments() != null) {
                 presenter.setArgumentDate(getArguments().getString(ARGUMENT_KEY));
             }
-
-            presenter.onStart(this, isPrimary);
+            presenter.onStart(this);
+            presenter.onFragmentActivated(isFragmentVisible);
         }
         return view;
     }
@@ -114,10 +102,9 @@ public class TimetableTabFragment extends BaseFragment implements TimetableTabCo
     @Override
     public void setMenuVisibility(boolean menuVisible) {
         super.setMenuVisibility(menuVisible);
-        if (presenter != null && getView() != null) {
-            presenter.onFragmentSelected(isSelected);
-        } else if (isSelected) {
-            isPrimary = true;
+        isFragmentVisible = menuVisible;
+        if (presenter != null) {
+            presenter.onFragmentActivated(menuVisible);
         }
     }
 
@@ -151,10 +138,6 @@ public class TimetableTabFragment extends BaseFragment implements TimetableTabCo
         noItemView.setVisibility(show ? View.VISIBLE : View.INVISIBLE);
     }
 
-    public void setSelected(boolean selected) {
-        isSelected = selected;
-    }
-
     @Override
     public void onError(String message) {
         if (getActivity() != null) {
@@ -163,15 +146,8 @@ public class TimetableTabFragment extends BaseFragment implements TimetableTabCo
         }
     }
 
-    @Override
-    public void onSaveInstanceState(@NonNull Bundle outState) {
-        outState.putBoolean(SAVED_KEY, isSelected);
-        super.onSaveInstanceState(outState);
-    }
-
     @Override
     public void onDestroyView() {
-        isPrimary = false;
         presenter.onDestroy();
         super.onDestroyView();
     }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableTabPresenter.java b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableTabPresenter.java
index 20d0b965b..dcfe2612c 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableTabPresenter.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/timetable/TimetableTabPresenter.java
@@ -36,21 +36,22 @@ public class TimetableTabPresenter extends BasePresenter<TimetableTabContract.Vi
     }
 
     @Override
-    public void onStart(TimetableTabContract.View view, boolean isPrimary) {
+    public void onStart(TimetableTabContract.View view) {
         super.onStart(view);
         getView().showProgressBar(true);
         getView().showNoItem(false);
-        onFragmentSelected(isPrimary);
     }
 
     @Override
-    public void onFragmentSelected(boolean isSelected) {
-        if (!isFirstSight && isSelected) {
+    public void onFragmentActivated(boolean isSelected) {
+        if (!isFirstSight && isSelected && isViewAttached()) {
             isFirstSight = true;
 
             loadingTask = new AbstractTask();
             loadingTask.setOnFirstLoadingListener(this);
             loadingTask.execute();
+        } else if (!isSelected) {
+            cancelAsyncTasks();
         }
     }
 
@@ -161,10 +162,7 @@ public class TimetableTabPresenter extends BasePresenter<TimetableTabContract.Vi
         getRepository().syncTimetable(date);
     }
 
-    @Override
-    public void onDestroy() {
-        isFirstSight = false;
-
+    private void cancelAsyncTasks() {
         if (refreshTask != null) {
             refreshTask.cancel(true);
             refreshTask = null;
@@ -173,6 +171,12 @@ public class TimetableTabPresenter extends BasePresenter<TimetableTabContract.Vi
             loadingTask.cancel(true);
             loadingTask = null;
         }
+    }
+
+    @Override
+    public void onDestroy() {
+        isFirstSight = false;
+        cancelAsyncTasks();
         super.onDestroy();
     }
 }
diff --git a/build.gradle b/build.gradle
index 999f91de6..28748fc06 100644
--- a/build.gradle
+++ b/build.gradle
@@ -7,9 +7,6 @@ buildscript {
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:3.0.1'
-
-        // NOTE: Do not place your application dependencies here; they belong
-        // in the individual module build.gradle files
         classpath "org.sonarsource.scanner.gradle:sonarqube-gradle-plugin:2.6.1"
         classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.7.3'
         classpath 'com.github.dcendents:android-maven-gradle-plugin:1.4.1'
@@ -29,6 +26,31 @@ subprojects {
 
 ext {
     GROUP_ID = "io.github.wulkanowy"
+
+    supportVersion = "26.1.0"
+    firebaseJob = "0.8.5"
+    apacheLang = "3.7"
+    apacheCollections = "4.1"
+    flexibleAdapter = "5.0.2"
+    flexibleUi = "1.0.0-b2"
+    greenDao = "3.2.2"
+    greenDaoHelper = "v2.0.2"
+    butterknife = "8.8.1"
+    jodaTime = "2.9.9"
+    dagger2 = "2.15"
+    ahbottom = "2.1.0"
+    jsoup = "1.10.3"
+    gson = "2.8.2"
+
+    debugDb = "1.0.3"
+    sqlcipher = "3.5.9"
+
+    junit = "4.12"
+    mockito = "2.16.0"
+    testRunner = "1.0.1"
+
+    crashlyticsSdk = "2.9.1"
+    crashlyticsAnswers = "1.4.1"
 }
 
 allprojects {