Fronto & SlideJoy - Make Money on Your Lockscreen
With these two money making apps you can earn money by unlocking your Android phone. Both of these only work on Android, and replace your lock screen.
You will see ads and offers on your lock screen, and every time you unlock or swipe to see more about the offer you can earn more money. You earn more points towards cash or gift cards by interacting with the ads.
If you hate ads, this is not the thing for you, but if you want a way to earn some money every time you unlock your Android phone, this is something to check out.