Thanks so much mahipal and silencio for the pointers, greatly appreciated.

I've reached the point where my app and its webapp counterpart are both technically complete, so I'm all about the polish now.

My app isn't groundbreaking (it's going to be living in the Entertainment category), but I think that the similar apps that are currently in the store suggest that there's a place for it. Most importantly, it allows users to be creative and share their product with others; I'm not the gatekeeper, just the groundskeeper (clean up after the animals that mess my garden).