diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/App.kt b/app/src/main/java/pl/szczodrzynski/edziennik/App.kt
index 4db63386..b3ec1cc3 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/App.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/App.kt
@@ -175,8 +175,8 @@ class App : MultiDexApplication(), Configuration.Provider, CoroutineScope {
         App.config = Config(App.db)
         App.profile = Profile(0, 0, 0, "")
         debugMode = BuildConfig.DEBUG
-        devMode = config.debugMode || debugMode
-        enableChucker = config.enableChucker || devMode
+        devMode = config.devMode ?: debugMode
+        enableChucker = config.enableChucker ?: devMode
 
         if (!profileLoadById(config.lastProfileId)) {
             db.profileDao().firstId?.let { profileLoadById(it) }
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/config/Config.kt b/app/src/main/java/pl/szczodrzynski/edziennik/config/Config.kt
index 8c9270f2..e29d93ad 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/config/Config.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/config/Config.kt
@@ -12,10 +12,7 @@ import kotlinx.coroutines.launch
 import pl.szczodrzynski.edziennik.App
 import pl.szczodrzynski.edziennik.BuildConfig
 import pl.szczodrzynski.edziennik.config.db.ConfigEntry
-import pl.szczodrzynski.edziennik.config.utils.ConfigMigration
-import pl.szczodrzynski.edziennik.config.utils.get
-import pl.szczodrzynski.edziennik.config.utils.set
-import pl.szczodrzynski.edziennik.config.utils.toHashMap
+import pl.szczodrzynski.edziennik.config.utils.*
 import pl.szczodrzynski.edziennik.data.api.szkolny.response.Update
 import pl.szczodrzynski.edziennik.data.db.AppDb
 import kotlin.coroutines.CoroutineContext
@@ -75,15 +72,15 @@ class Config(val db: AppDb) : CoroutineScope, AbstractConfig {
         get() { mPrivacyPolicyAccepted = mPrivacyPolicyAccepted ?: values.get("privacyPolicyAccepted", false); return mPrivacyPolicyAccepted ?: false }
         set(value) { set("privacyPolicyAccepted", value); mPrivacyPolicyAccepted = value }
 
-    private var mDebugMode: Boolean? = null
-    var debugMode: Boolean
-        get() { mDebugMode = mDebugMode ?: values.get("debugMode", false); return mDebugMode ?: false }
-        set(value) { set("debugMode", value); mDebugMode = value }
+    private var mDevMode: Boolean? = null
+    var devMode: Boolean?
+        get() { mDevMode = mDevMode ?: values.getBooleanOrNull("debugMode"); return mDevMode }
+        set(value) { set("debugMode", value?.toString()); mDevMode = value }
 
     private var mEnableChucker: Boolean? = null
-    var enableChucker: Boolean
-        get() { mEnableChucker = mEnableChucker ?: values.get("enableChucker", false); return mEnableChucker ?: false }
-        set(value) { set("enableChucker", value); mEnableChucker = value }
+    var enableChucker: Boolean?
+        get() { mEnableChucker = mEnableChucker ?: values.getBooleanOrNull("enableChucker"); return mEnableChucker }
+        set(value) { set("enableChucker", value?.toString()); mEnableChucker = value }
 
     private var mDevModePassword: String? = null
     var devModePassword: String?
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/config/utils/ConfigExtensions.kt b/app/src/main/java/pl/szczodrzynski/edziennik/config/utils/ConfigExtensions.kt
index c98cf832..94bb87e6 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/config/utils/ConfigExtensions.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/config/utils/ConfigExtensions.kt
@@ -59,6 +59,9 @@ fun HashMap<String, String?>.get(key: String, default: String?): String? {
 fun HashMap<String, String?>.get(key: String, default: Boolean): Boolean {
     return this[key]?.toBoolean() ?: default
 }
+fun HashMap<String, String?>.getBooleanOrNull(key: String): Boolean? {
+    return this[key]?.toBooleanStrictOrNull()
+}
 fun HashMap<String, String?>.get(key: String, default: Int): Int {
     return this[key]?.toIntOrNull() ?: default
 }
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/config/utils/ConfigMigration.kt b/app/src/main/java/pl/szczodrzynski/edziennik/config/utils/ConfigMigration.kt
index 1095f511..58dc35f7 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/config/utils/ConfigMigration.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/config/utils/ConfigMigration.kt
@@ -67,7 +67,7 @@ class ConfigMigration(app: App, config: Config) {
         if (dataVersion < 3) {
             update = null
             privacyPolicyAccepted = false
-            debugMode = false
+            devMode = null
             devModePassword = null
             appInstalledTime = 0L
             appRateSnackbarTime = 0L
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/debug/LabFragment.kt b/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/debug/LabFragment.kt
index 60c30cf9..f7c8952d 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/debug/LabFragment.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/debug/LabFragment.kt
@@ -41,6 +41,7 @@ class LabFragment : Fragment(), CoroutineScope {
         app = activity.application as App
         b = TemplateFragmentBinding.inflate(inflater)
         b.refreshLayout.setParent(activity.swipeRefreshLayout)
+        b.refreshLayout.isEnabled = false
         return b.root
     }
 
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/debug/LabPageFragment.kt b/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/debug/LabPageFragment.kt
index 4d8205bf..19ae4697 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/debug/LabPageFragment.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/debug/LabPageFragment.kt
@@ -16,6 +16,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.launch
 import pl.szczodrzynski.edziennik.*
+import pl.szczodrzynski.edziennik.config.Config
 import pl.szczodrzynski.edziennik.data.db.entity.Event
 import pl.szczodrzynski.edziennik.databinding.LabFragmentBinding
 import pl.szczodrzynski.edziennik.ui.dialogs.profile.ProfileRemoveDialog
@@ -78,10 +79,10 @@ class LabPageFragment : LazyFragment(), CoroutineScope {
             app.db.eventDao().getRawNow("UPDATE events SET homeworkBody = NULL WHERE profileId = ${App.profileId}")
         }
 
-        b.chucker.isChecked = app.config.enableChucker
-
+        b.chucker.isChecked = App.enableChucker
         b.chucker.onChange { _, isChecked ->
             app.config.enableChucker = isChecked
+            App.enableChucker = isChecked
             MaterialAlertDialogBuilder(activity)
                 .setTitle("Restart")
                 .setMessage("Wymagany restart aplikacji")
@@ -94,9 +95,9 @@ class LabPageFragment : LazyFragment(), CoroutineScope {
                 .show()
         }
 
-
         b.disableDebug.onClick {
-            app.config.debugMode = false
+            app.config.devMode = false
+            App.devMode = false
             MaterialAlertDialogBuilder(activity)
                 .setTitle("Restart")
                 .setMessage("Wymagany restart aplikacji")
@@ -115,6 +116,14 @@ class LabPageFragment : LazyFragment(), CoroutineScope {
             app.profileSave()
         }
 
+        b.resetCert.onClick {
+            app.config.apiInvalidCert = null
+        }
+
+        b.rebuildConfig.onClick {
+            App.config = Config(App.db)
+        }
+
         val profiles = app.db.profileDao().allNow
         b.profile.clear()
         b.profile += profiles.map { TextInputDropDown.Item(it.id.toLong(), "${it.id} ${it.name} archived ${it.archived}", tag = it) }
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/login/LoginPrizeFragment.kt b/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/login/LoginPrizeFragment.kt
index 1c9634fc..f14c6d19 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/login/LoginPrizeFragment.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/login/LoginPrizeFragment.kt
@@ -53,7 +53,7 @@ class LoginPrizeFragment : Fragment(), CoroutineScope {
                     .setTitle(R.string.are_you_sure)
                     .setMessage(R.string.dev_mode_enable_warning)
                     .setPositiveButton(R.string.yes) { _, _ ->
-                        app.config.debugMode = true
+                        app.config.devMode = true
                         App.devMode = true
                         MaterialAlertDialogBuilder(activity)
                                 .setTitle("Restart")
@@ -67,8 +67,8 @@ class LoginPrizeFragment : Fragment(), CoroutineScope {
                                 .show()
                     }
                     .setNegativeButton(R.string.no) { _, _ ->
-                        app.config.debugMode = false
-                        App.devMode = false
+                        app.config.devMode = App.debugMode
+                        App.devMode = App.debugMode
                         activity.finish()
                     }
                     .show()
diff --git a/app/src/main/res/layout/lab_fragment.xml b/app/src/main/res/layout/lab_fragment.xml
index 6c4bca77..d0756d7f 100644
--- a/app/src/main/res/layout/lab_fragment.xml
+++ b/app/src/main/res/layout/lab_fragment.xml
@@ -1,15 +1,17 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
+<?xml version="1.0" encoding="utf-8"?><!--
   ~ Copyright (c) Kuba Szczodrzyński 2020-4-3.
   -->
 
-<layout xmlns:app="http://schemas.android.com/apk/res-auto"
+<layout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
-    xmlns:android="http://schemas.android.com/apk/res/android"
     tools:ignore="HardcodedText">
 
     <data>
-        <variable name="app" type="pl.szczodrzynski.edziennik.App"/>
+
+        <variable
+            name="app"
+            type="pl.szczodrzynski.edziennik.App" />
     </data>
 
     <ScrollView
@@ -39,7 +41,7 @@
                 android:layout_height="match_parent"
                 app:layout_behavior="@string/appbar_scrolling_view_behavior" />-->
 
-            <Switch
+            <com.google.android.material.checkbox.MaterialCheckBox
                 android:id="@+id/chucker"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
@@ -87,7 +89,7 @@
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:fontFamily="monospace"
-                tools:text="Cookies:\n\nsynergia.librus.pl\n    DZIENNIKSID=L01~1234567890abcdef"/>
+                tools:text="Cookies:\n\nsynergia.librus.pl\n    DZIENNIKSID=L01~1234567890abcdef" />
 
             <Button
                 android:id="@+id/unarchive"
@@ -99,9 +101,9 @@
 
             <pl.szczodrzynski.edziennik.utils.TextInputDropDown
                 android:id="@+id/profile"
+                style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
                 android:layout_width="match_parent"
-                android:layout_height="wrap_content"
-                style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox" />
+                android:layout_height="wrap_content" />
 
             <com.google.android.material.checkbox.MaterialCheckBox
                 android:layout_width="match_parent"
@@ -109,13 +111,36 @@
                 android:checked="@={app.config.archiverEnabled}"
                 android:text="Archiver enabled" />
 
+            <com.google.android.material.checkbox.MaterialCheckBox
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:checked="@={app.config.apiAvailabilityCheck}"
+                android:text="Availability check enabled" />
+
+            <Button
+                android:id="@+id/resetCert"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:text="Reset API signature"
+                android:textAllCaps="false" />
+
             <Button
                 android:id="@+id/disableDebug"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
+                android:layout_marginTop="24dp"
                 android:text="Disable Dev Mode"
                 android:textAllCaps="false"
                 app:backgroundTint="@color/windowBackgroundRed" />
+
+            <Button
+                android:id="@+id/rebuildConfig"
+                style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginBottom="16dp"
+                android:text="Rebuild App.config"
+                android:textAllCaps="false" />
         </LinearLayout>
     </ScrollView>
 </layout>