Calculate+4 -simple calculator

I made the concept that, want to use a calculator on a tablet and also want to use a calculator with a simple design. The buttons are large and easy to touch, and have a simple design. In calculator + 4 we put four calculators on one screen when we turned horizontally. I think that it is useful in various places if you have to do simultaneous calculation. [Major features]: -Simple and easy design -The button is large and easy to touch -When turned horizontally, equipped with four calculators can be calculated simultaneously -For portrait orientation, delete the rightmost value with backspace button -Percent calculation also possible -Supports both vertical and horizontal display -Display comma (,) in every three digits for easy reading of calculation result Supported Operators: -Basic operations: +,-, x, ÷,% -+/- conversion If you have any comments or suggestions about this app, please contact us anytime