This application is a Compound (Time Value of Money) and Simple interest calculator (Savings/Loan, etc.). (Same kind calculation as [FV][PV][PMT][I%][N] key on financial calculator)
It equips User Interface suitable for Touchscreen. (Direct touch to displayed number works as number input or modification, or switching between result and input.)
If you have been using Surface Pro,2in1 PC, etc., it will reduce working time. Please try this application.
(It can be controlled from Mouse, TouchPad. But direct feeling fades a little.)