we've recently rediscovered the powers of youtube and deep sleep soundtracks. easily pulled up on your phone while it's charging, a quick search rendered a ton of deep sleep soundtracks to doze off to. i find that i fall asleep within 30 minutes so the shorter tracks work well for me, but if you are an insomniac or tend to wake up in the middle of the night, you can pick out an 8+ hour one too! just remember to face your phone upside down, so the display light doesn't keep you up!