Mini Metronome is a reference metronome that
uses minimum screen estate.
The deficiency that the volume of this metronome is outrageously low is acknowledged but not addressed due to the incompetence of the developer.
One possible application of this low volume metronome is
Get a tempo for a song by tapping or guessing:
Clicking on the tempo panel yields the tempo control window. You can either tap on the button at the top or enter a tempo directly in the text field