tachiyomi/app/src/main/res/layout/main_activity_fab.xml

<?xml version="1.0" encoding="utf-8"?>
<com.google.android.material.floatingactionbutton.ExtendedFloatingActionButton xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/root_fab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_margin="16dp"
    android:layout_gravity="bottom|end"
    android:minWidth="0dp"
    android:visibility="gone"
    tools:icon="@drawable/ic_help_24dp"
    tools:text="Action"
    tools:visibility="visible" />