It is the metronome which it is simple and can operate.
I omit many functions and make it minimum.
The metronome is essential to the exercise of the musical instrument, but carrying around is recommended for a person to be troublesome.
Main characteristic:
I can choose a tempo, the choice of the time with a slide bar easily.
The tempo can set 20-300, the beat to 1-7.
A tempo of the distance that I clicked is set when I click two times of tap buttons.