This is the simple calculator that has the function of bracket, log and involution.
To use functions that displayed to small on the edge of buttons, You can flick the button for the direction.

To change the background image/color, Tap the button of menu.
and, to copy the result or paste the value, Tap the button on the actionbar.

This app is developed for study, so I can't guarantee the result of calculation and behavior of app.
Please note that.