Using WaveUp, just wave your hand over the proximity sensor of your phone to turn the screen on. This is called wave mode and can be disabled in the settings screen in order to avoid accidental switching on of your screen.
It will also turn on the screen when you take your smartphone out of your pocket or purse. This is called pocket mode and can also be disabled in the settings screen.
Both of these modes are enabled by default.
It also locks your phone and turns off the screen if you cover the proximity sensor for one second. This does not have a special name but can nonetheless be changed in the settings screen too. It is also enabled by default.
For those who have never heard proximity sensor before: it is a small thingie that is somewhere near where you put your ear when you speak on the phone. You practically can't see it and it is responsible for telling your phone to switch off the screen when you're on a call.
Required Android Permissions:
WAKE_LOCK to turn on the screen
USES_POLICY_FORCE_LOCK to lock the device
RECEIVE_BOOT_COMPLETED to automatically startup on boot if selected
READ_PHONE_STATE to suspend WaveUp while on a call