I have the best and most amazing idea for your app use the power of "community" to get more reviews, user, learning material, etc. Get some so called professional artist and make them riview your artwork. They will be happy if they see improvement and will give advice if you need improvement. "But that will cost us quite the money" that's when the so called "community" comes in and do free work. I got more ideas if you need it contact me. I don't need payment i need a "favor" in return for more