This calculator can calculate the fastest of all calculators. Flicking, you can input +-*/ in the same time with number. e.g. If you type like below, , , , [4(with flicking left)], ,  it means "123+456".
In addition, this calculator doesn't have "=" key. That is because you don't have to press it. Flick Calc Kyu show the answer right after your typing.
English and Japanese are available (depending on the device setting).