Here's one that's just for fun with a tinge of curiousity. Sleep Recorder is a unique app that records sounds while you sleep. If you have heard that you talk in your sleep at night and want to hear what you say, this is your opportunity. Or if you just want to make sure one of your family members isn't sneaking into your room at night Paranormal Activity style, this will help catch them in the act. The app only records sounds and won't save what's recorded during silence. So when you wake up, all you have to do is hit play to heat the greatest hits of the night.