UndoableMemo is an application that enables you to undo/redo infinitelyWhat do you think when you delete all sentences by mistake? I think you want something in Windows like the "ctrl+z" in Android. But Android does not support even one time undo. This app allows you to go back to the past like time machine while you are editing text.Features* Undo/redo infinitely (as long as possible)* Save automatically (and you can resume)How to use* Touch the left allow button to undo* Touch the right allow button to redo* Scroll the seekbar to backward and forward freelyFor more details [Japanese]: http://usi3.com/UndoableMemo