I have two great (and free) Android apps for you today:
Easy Mute will pause or mute music and podcasts on your phone just by placing your hand over the device. It uses the proximity sensor and you can tell it to only activate if the phone is lying flat.
It works great and it remembers it’s state when the phone is moved. This confused me at first but to replicate, cover the front of the camera to pause and then lift the phone. It will still be paused when you lift your hand off the front. After putting the phone down wave your hand over the front again and it will resume (or just unlock and hit play, the old fashioned way). (via)