Is there a tweak to set a custom action to Undo? The Shake to undo (Etch-a-Sketch style) feature of iOS is nice, but Id like to be able to set another action for Undo instead of Shake. Ideally, Id like a keyboard mod where you hold down a key. Perhaps holding down the delete key could pop up an Undo/Redo menu, similar to how accented letters appear. Or perhaps holding down Shift could turn the Space Bar into and Undo key, much like Delete Word lets Shift change the Delete key into Delete Word. At the very least, an Activator action to call the Undo method would be nice. Is anything like this possible?