Ambiance 

Have trouble sleeping? Just need to relax? Ambiance combines sound and pictures to do just this. After purchasing the app you can download over 550 environments, which include both sound and image, from its free online store. Ambiance also has a fully customizable alarm clock which lets you fall asleep as one sound fades out, and awake as another fades back in at the time of your choosing. Other features include dimming of your screen, marking sounds as favorites and even integration of your devices library. With the online store being updated every week, you are sure to find the right environments for you.