Right off the bat I would say a public gallery would be neat and engaging. It's really easy to make something beautiful with this (!), so if you create a public

Right off the bat I would say a public gallery would be neat and engaging. It's really easy to make something beautiful with this (!), so if you create a public forum for sharing & competing to make something even cooler, you could probably catch a lot of eyeballs, and monetize that way. Then your growth comes down to keeping people engaged with new / fun ways to make art easily.