AddIt - The adding machine for your mobile device. Much more than a calculator. Entries in the running list can be edited and the list automatically recalculates! AddIt is designed to function like an adding machine/calculator with a running tape. As calculations are completed, they are added to a running list of calculations. Items in the list can then be easily changed. If there is a mistake somewhere in your list of calculations, you can go back and change the incorrect number.