wulkanowy-mod/app/src/main/res/layout/activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="leszcz_team.wulkanowy.activity.main.MainActivity"
    tools:layout_editor_absoluteY="81dp"
    tools:layout_editor_absoluteX="0dp">

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="426dp"
        android:text="@string/app_name"
        android:textSize="40dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        tools:layout_constraintBottom_creator="1"
        tools:layout_constraintLeft_creator="1"
        tools:layout_constraintRight_creator="1" />

    <EditText
        android:id="@+id/passwordText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:inputType="textPassword"
        android:hint="@string/pass_hint"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_bias="0.502"
        tools:layout_constraintTop_creator="1"
        tools:layout_constraintRight_creator="1"
        tools:layout_constraintBottom_creator="1"
        app:layout_constraintVertical_chainStyle="spread_inside"
        tools:layout_constraintLeft_creator="1" />

    <EditText
        android:id="@+id/emailText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:inputType="textEmailAddress"
        android:hint="@string/email_hint"
        app:layout_constraintVertical_chainStyle="spread_inside"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintHorizontal_bias="0.502"
        tools:layout_constraintRight_creator="1"
        tools:layout_constraintBottom_creator="1"
        app:layout_constraintBottom_toTopOf="@+id/passwordText"
        tools:layout_constraintLeft_creator="1"
        android:layout_marginBottom="45dp" />

    <Button
        android:id="@+id/agreeButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/login_button"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        tools:layout_constraintTop_creator="1"
        tools:layout_constraintRight_creator="1"
        android:layout_marginTop="58dp"
        app:layout_constraintTop_toBottomOf="@+id/passwordText"
        tools:layout_constraintLeft_creator="1" />

</android.support.constraint.ConstraintLayout>