Android: Smart Screen On is an Android utility that turns your phone's proximity sensor into a substitute power button that can turn your display on or off with a simple wave over the front of your device. If you're sitting in class and want to see what that notification is without picking up your phone, wave your hand over it to turn the display on. Then, with another wave, turn the screen back off.
If this app sounds familiar, it should. XDA forum member DDeleted wrote this app as a sequel of sorts to the previously mentioned Smart Screen Off, which would only turn the screen off when you put your hand over the proximity sensor. Smart Screen On includes this feature, but gives you more control over what you can do with the proximity sensor.
For example, you can now control how long the app waits between waves in order to perform a specific action -- you can tell the app to only turn the screen on or off after more than one wave, and you can even set the interval between waves so the app doesn't turn your screen on or off accidentally. Another interesting feature in Smart Screen On is called "Tap and Swipe", where you actually put your finger over the proximity sensor, wait for the app to vibrate, and then move your finger before the second vibration to either turn the phone on or off.
DDeleted built the app as a way to save your physical power button from wear and damage -- especially on devices like the Galaxy Nexus or the Galaxy S III, which have no other physical buttons. That's a good reason, but we can see some enterprising Tasker fans rolling this app and its features into some Tasker actions that leverage the proximity sensor. Smart Screen On comes in two flavours, the free Lite version and the $2 Pro version, which gets you. Both are available now at Google Play. For more details, hop over to the XDA developer forums below.
[APP] Smart Screen ON [XDA-developers]