Didn't realise this post was still getting replies as I don't frequent the forum often.
As for the type of game, I mentioned in my first post it's not really a game, it would be something similar to Army Builder/Battle Scribe. I just used game levels as an example of sharing user created levels without the need of a server in the middle. The Army Builder app is for table top wargamers to help build their armies to play with. The legal issues with these kind of apps is that the data that users create and share in these army building type of apps has a lot of information about every single character and infantry type for each army and game, that you could almost do away with not needing and buying the relevant rulebooks that are sold for these game systems. I think they get away with not being liable because they don't sell the program with all that data in, and some of them don't host these army data files on their own servers. Everything is user created and shared amongst users via other methods like forums, github, and email etc.
That was why I was interested in finding out how to share such data through the app using images that contained all of that data embedded.
I've been thinking again about this app again lately and may have another go. But I may actually use a central server to host the files, because those files would now just be blank templates so users would still need to own the rule books for the games they play. Users won't be able to share files that has data for the armies included.
I did start doing it in AppGameKit but will move it to another language as I don't think it's suitable for it.