iOS (jailbroken): If you tend to place your iPhone on a table when you're not using it, then you know how the vibration can suddenly be startling or become unexpectedly annoying. MyVibe automatically turns off the vibration any time the phone is on a flat surface.
When your device is on a flat surface, the vibration function is turned off so it doesn't make that annoying and grating sound on a table. You can set the sensitivity of MyVibe in a few different ways so that it doesn't accidentally turn on in your pocket.
In my experience, when the sensitivity was on high, MyVibe wouldn't turn on when it was just sitting in my pocket. You can also enable an upside down silencer that turns on Do Not Disturb when the phone is face down, so you don't receive notifications at all. If you leave your phone out on a table a lot, MyVibe is well worth checking out.