توضیحات:

This is a simple counter that can count four numbers at the same time.
Because the button is large, there is no mistake in pushing.
You can copy the counted result and paste it to other apps.
You can also copy four numbers at once.
(A character string with "," interposed between four numbers is created.)
The result of counting is saved even if you close the app or turn off the smartphone or tablet, so you can count from the rest.
You can set whether to sound or vibrate when the button is pressed.