Automatically locks phone when flipped face down or placed in your pocket (upside down).
Warning: Proximity sensor may use battery.
It's made for my phone. If it doesn't work for you, be smart and fix it. It's likely the proximity sensor outputting something other than a 0 or your gyros are inverted from mine.
Update 2: Tightened tolerances to reduce false locks. Added a delay between triggers to turn off the proximity sensor.
Update 3: Previously, if your sensor output a 0 after the delay was over, it wouldn't lock unless sensor was set to 1 then back to 0. Ie: flipping over and back
Rate and review within the app in the Community section.