Hey, check out Locket. It's an Android app that pays you for unlocking your phone. The way it's done is simple. By downloading the app, you basically rent out your lock screen to brands. At one swipe, you can either open the ad, or unlock your phone the way you always do.
Every time you unlock your phone (up to three times per hours) you get $0.01. Every friend that you have who signed up using your link gets you $1.00 right now.