Calc Though

This is a simple calculator application.
Because many calc apps (for free) don't have thousands separator, I made this app.
Significant digits are 15.
Short piano sol-fa tones were assigned to key input tones for number buttons from "0" to "9".
(button "1" is C1 and button "8" is C2.)
If you want to control the mute of the tone, please long press "C" button and select a button on a dialog.