The Locket app lets you make money every time you open your phone. The app is currently an Android exclusive and works in the simplest manner possible. All you need to do is install the app, let your phone sleep and voila! Now when you go to open your phone, your lock screen will have an ad on it.
You can either interact with the ad by swiping left or ignore it by swiping right. No matter what you do, you will make a cent. Although this may seem like a low figure, because it is, it's more than you would make for opening your phone should you not have the Locket app installed. Payments max out at 0.03 an hour and $15 monthly. Users can cash out at the end of the month, apply their funds to a gift card or donate them to charity!