trkpt/app/src/main/res/layout/activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
    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"
    android:fitsSystemWindows="true"
    tools:context="org.y20k.trackbook.MainActivity">

    <android.support.constraint.ConstraintLayout
        android:id="@+id/container"
        android:layout_width="match_parent"
        android:layout_height="match_parent">


        <!-- BUTTON MY LOCATION -->
        <android.support.design.widget.FloatingActionButton
            android:id="@+id/fabLLcationButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="16dp"
            android:clickable="true"
            app:backgroundTint="@color/trackbook_white"
            app:fabSize="mini"
            app:layout_constraintBottom_toBottomOf="@+id/fabMainButton"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="@+id/fabMainButton"
            app:srcCompat="@drawable/ic_my_location_grey_24dp" />


        <!-- BUTTON SAVE AND CLEAR -->
        <android.support.design.widget.FloatingActionButton
            android:id="@+id/fabSubMenuButtonSave"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="16dp"
            android:contentDescription="@string/descr_fab_sub_menu_button_1"
            app:backgroundTint="@color/trackbook_green"
            app:fabSize="mini"
            app:layout_constraintBottom_toTopOf="@+id/fabSubMenuButtonClear"
            app:layout_constraintEnd_toEndOf="@+id/fabSubMenuButtonClear"
            app:layout_constraintStart_toStartOf="@+id/fabSubMenuButtonClear"
            app:srcCompat="@drawable/ic_save_white_24dp" />

        <android.support.v7.widget.CardView
            android:id="@+id/fabSubMenuLabelSave"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom|end"
            android:layout_marginEnd="8dp"
            android:contentDescription="@string/descr_fab_sub_menu_button_1"
            app:cardBackgroundColor="@color/trackbook_white"
            app:cardCornerRadius="4dp"
            app:cardElevation="4dp"
            app:cardUseCompatPadding="true"
            app:layout_constraintBottom_toBottomOf="@+id/fabSubMenuButtonSave"
            app:layout_constraintEnd_toStartOf="@+id/fabSubMenuButtonSave"
            app:layout_constraintTop_toTopOf="@+id/fabSubMenuButtonSave">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:paddingBottom="2dp"
                android:paddingLeft="6dp"
                android:paddingRight="6dp"
                android:paddingTop="2dp"
                android:text="@string/fab_sub_menu_save_and_clear"
                android:textAppearance="?android:attr/textAppearanceSmall"
                android:textStyle="bold"
                tools:layout_editor_absoluteX="110dp"
                tools:layout_editor_absoluteY="239dp" />
        </android.support.v7.widget.CardView>


        <!-- BUTTON CLEAR -->
        <android.support.design.widget.FloatingActionButton
            android:id="@+id/fabSubMenuButtonClear"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="16dp"
            android:contentDescription="@string/descr_fab_sub_menu_button_2"
            app:backgroundTint="@color/trackbook_blue"
            app:fabSize="mini"
            app:layout_constraintBottom_toTopOf="@+id/fabMainButton"
            app:layout_constraintEnd_toEndOf="@+id/fabMainButton"
            app:layout_constraintStart_toStartOf="@+id/fabMainButton"
            app:srcCompat="@drawable/ic_clear_white_24dp" />

        <android.support.v7.widget.CardView
            android:id="@+id/fabSubMenuLabelClear"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginEnd="8dp"
            android:contentDescription="@string/descr_fab_sub_menu_label_2"
            app:cardBackgroundColor="@color/trackbook_white"
            app:cardCornerRadius="4dp"
            app:cardElevation="4dp"
            app:cardUseCompatPadding="true"
            app:layout_constraintBottom_toBottomOf="@+id/fabSubMenuButtonClear"
            app:layout_constraintEnd_toStartOf="@+id/fabSubMenuButtonClear"
            app:layout_constraintTop_toTopOf="@+id/fabSubMenuButtonClear">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:paddingBottom="2dp"
                android:paddingLeft="6dp"
                android:paddingRight="6dp"
                android:paddingTop="2dp"
                android:text="@string/fab_sub_menu_clear"
                android:textAppearance="?android:attr/textAppearanceSmall"
                android:textStyle="bold"
                tools:layout_editor_absoluteX="124dp"
                tools:layout_editor_absoluteY="447dp" />
        </android.support.v7.widget.CardView>


        <!-- MAIN BUTTON -->
        <android.support.design.widget.FloatingActionButton
            android:id="@+id/fabMainButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="16dp"
            android:layout_marginEnd="16dp"
            android:contentDescription="@string/descr_fab_main"
            app:backgroundTint="@color/trackbook_blue"
            app:fabSize="normal"
            app:layout_constraintBottom_toTopOf="@+id/navigation"
            app:layout_constraintEnd_toEndOf="parent"
            app:srcCompat="@drawable/ic_fiber_manual_record_white_24dp" />


        <!-- BOTTOM NAVIGATION -->
        <android.support.design.widget.BottomNavigationView
            android:id="@+id/navigation"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:background="@color/trackbook_red"
            app:itemIconTint="@drawable/selector_bottom_navigation"
            app:itemTextColor="@drawable/selector_bottom_navigation"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:menu="@menu/menu_main" />

    </android.support.constraint.ConstraintLayout>
</android.support.design.widget.CoordinatorLayout>