In the best case the "data recovery" function should be merged with an "automatic session save/restoration process". Several points here:

• when we quit Aseprite, we should be able to open it again with all sprites + undo information restored (as if we have never closed the program)
• if the program crashes, we should be able to open it again and all the information is restored exactly as moments (30 seconds?) before the crash

Some problems:

• what happens if we start editing a file, close Aseprite, replace that file with an older version from the file manager, and start Aseprite again, should we restore the undo information? solution: Aseprite should check that the restored file is exactly the same as in the session, so undo information can be restored (e.g. keep a sha1 checksum of the original file associated with the session information)
• what happens if two or more instances are running at the same time? we may keep these two sessions separated, but then when we open Aseprite again what should we do? merge both sessions? open the first one and if another Aseprite instance is executed open the second one? should the first instance open another window (instance) of aseprite with the second session?
• what should we do when Aseprite is opened just to edit a file? should we load the entire session?

And finally, make this optional.