Locket is a legit app that was recently launched on the Google Play Store, where it enables a bunch of advertisers (the selection seems to be rather limited at the moment, simply because it has yet to gain momentum – do expect it to increase in due time should the idea catch on) to place an ad on your lock screen, and you are paid a single cent each time you unlock your device. Of course, this will be limited to just $0.03 an hour, and you can then opt to cash out, use the accumulated funds on a gift card, or even to make a donation to your favorite charity. Of course, if you were to unlock your device’s display three times a day round the clock throughout the whole year, you would get $262.80. In reality, it would be a whole lot less since you do need to sleep, don’t you?