TableCalc for iPhone

From Sergey Petrov:

TableCalc is a calculator which allows you to review and edit every part of your calculations. All your actions are remembered so you can undo or redo each step. The order of the calculations is modifiable by the use of brackets. You can scroll through the calculator view, and change, add, or remove values and operations. The last calculation is saved when the application is closed so you can work on it later on.