Hi,
I have tried to build your app, and found there is a compatibility in the ProgressBar of MainActivity.
In the file content_main.xml
, you declare a ProgressBar as
<ProgressBar android:layout_alignParentBottom="true" android:minHeight="4dip" android:maxHeight="4dip" android:layout_width="fill_parent" android:layout_height="wrap_content" style="@android:style/Widget.ProgressBar.Horizontal" android:progressBackgroundTint="@color/colorPrimary" android:progressBackgroundTintMode="src_over" android:progressTint="@color/colorAccent" android:id="@+id/progressBar" />
Notice that android:progressBackgroundTintMode="src_over" works not good below API 23, to fix this you may avoid using this attribute. See the screenshot below.
API 23
API 22