TranquilityTV (free with in-app purchases) is designed to help you relax with videos of restful places and soothing audio. This universal app is a four-minute sampler of images and sounds before any IAP's.
The company behind the app makes videos for special TV channels in hospitals, and I could see why these scenes would be desirable rather than endless game shows or soap operas which is much of the daily TV fare.
I watched the sampler video, which is basically a compilation, and then tried one of the US$1.99 in-app purchases called High Altitude Meditation. It consists of views of the earth from space, clouds, mountain ranges etc.
The idea for this app is a good one. The execution is not, in my view, first rate. The videos do not look like high resolution at all. On my iPhone 5s and my iPad (3rd generation) they have the look of a VHS tape. The audio does better. The compositions are original, and in stereo. Of course that is best appreciated on headphones or external speakers. The purchased videos are 15 minutes in length, and don't repeat, so I find them a little short for the intended purpose. The app does include a sleep timer function.
TranquilityTV requires iOS 6 or later, and it is optimized for the iPhone 5. I think with better video quality, and longer videos with repeat, the app would be very attractive. If you are interested in this type of app, download the demo and see if it meets your needs.
For an alternative with much higher video quality check out Magic Window ($2.99) in the app store. It has breathtaking images with soothing ambient sounds.