GRAVITY SCREEN OFF
This app is amazing, and is especially useful for our aging phones. The power button failure is a well documented and increasingly common issue, so something like this not only saves the hardware but also allows you to customize the settings to whatever you're looking for.
Please go there and 'thank' plexnor for his work, and I'm pretty sure you'll love it. It's especially great for those who aren't using one of the 2 siyah variants built for us (AJK and STI) that have the swipe2wake feature; this app does away with the need to use the feature.
UPDATE: the permission READ PHONE STATUS AND IDENTITY is needed so that the app can suspend itself during calls (per plexnor).
all credit for screens goes to plexnor, and a special thanks to kantjer for bringing plexnor's work to my attention.