This would definitely be a useful feature that we would use. We have a similar use case to the poster in this suggestion in that we sometimes need edits to a previously saved submission and just want to be able to see if an edit was made (when and by whom).
An audit trail, as suggest in the associated suggestions (Update an already-submitted record on a mobile client - #7 by nat) would be nice but just being able to the date of when last edited and by whom would be hugely useful and probably much simpler to implement!
