It depends on how nice you want it to be. I already have cheat code, since I cannot test stuff in a sensible way without that. I disable it before the release
The thing is, I'm not sure I really want to make it too easy to use cheats, because I'm sure it will spoil the fun and gameplay for a lot of ppl. Even though some would like to have it.
Also the way the game is build, stats are not everything. Cheating on gamaday, quests and maybe even random events wil be a lot harder and you have to be very careful not to break anything.
Creating a cheat app for the phone to change player and girl stats would take some hours of programming.