A free program for Android, by schoettler Software GmbH.

CalcTape Calculator with Tape is a combination of a standard calculator app, a classic desktop calculator, and a notebook.

CalcTape can be considered a “spreadsheet with a calculator interface”. You can also create templates and place only those buttons on your keypad that you really need everyday.

If you do a long calculation with many figures and want to check if you entered the last figure correctly, you can easily do it by checking the result in place. The app allows you to insert a missing figure in the calculation and check if it is correct. You can place the cursor anywhere you like in the calculation and change the numbers or operators in the calculation.

You can also create a custom function. The function can be used to calculate any number. You can add an operator to any number and the result will be adjusted. You can also change the result and the number of the function. You can even add the percentage rate to any amount and it will be added to the result.