The Android operating system and "Task killer" software may automatically kill apps in the background when your device is running very low on memory. For that reason, you're advised to save your work regularly, especially before loading many new apps. (To help reduce memory use, all but the last two "undo" editing changes are abandoned whenever DubScript is put in the background.)
If DubScript should unexpectedly quit (battery runs out, out of memory, crash, accidentally killed, etc.) before you saved your changes, you may still be able to recover some of your changes.
DubScript attempts to save your work locally on your device as you edit, so check out the menu item that will allow you to recover should something bad happen.