I'll give you 1: A Mobile app review exchange program

Something like LinkExchange for mobile apps. A legitimate service where users exchange reviews in the App Store. But you don't have the obligation to write a positive one. The service is meant to give both parties some initial social proof, and constructive feedback on what needs to be improved.

I'm not talking about fake paid reviews you can buy for $10 for 50 or whatever. I'm talking about real reviews from users who actually downloaded the app and tried it.