Twin Key Calculator app for iPhone and iPad

There are two ten-keys in a calculator. It is convenient. In case of 2 numbers of calculation, you can decrease 1step. Its 3steps calculation.

Usage
-Enter left value with left key(s) and enter right value with rigtht key(s). Then push a operator key.
-Each ANS key can copy answer value to fomula.
-Round off slider doesnt need recalculation to show ronded value.
-After calculation you dont need to use "C" or "AllClear" for next calculation.

It is convinient in the following calculation repeatedly.
-Rate calculation
-Unit conversion
-Tax or tip calculation
-Batting average

Specification
10digits