[mehrzad]

1 tip for making a good app: gamify as little as possible.

Users don't want to feel rewarded for something that's probably wasting their time. They want to know that the action itself is useful. If your app can't do that, how will you retain users? I guess there are still a lot of people are willing to use pointless apps that track which Wikipedia articles they read and give them a gold star, but most people aren't.