One of my favourites
I have several ambient sound apps. This is one of my favourites because you can make your own soundscape by mixing sounds but also because you can set it as a wake up alarm or set it to run for a certain amount time and then fade out (you can also choose the length of time it fades out over). This helps me fall asleep (another app I have either cuts off abruptly or plays all night--which interferes with my sleep).
Anysia07 about
Relax Melodies P: Sleep Sounds, v5.2