Noizio, focus, relax, sleep

Noizio mixes ambient sounds into a background of your own: white noise, rain, ocean waves and dozens more, each with its own volume slider, saved as a mixture you can share with a friend or import from theirs. A sleep timer fades the sound out gently at a set length or an exact time, and playback keeps going in the background and on the lock screen. It pauses when headphones come out, resumes after a call, and does not interrupt other music until you press play.

It is a one-time purchase with no subscription, ads, account or internet requirement, which is rare in this category. There are no guided meditations or sleep stories, only sound. People who work in noisy places, light sleepers and anyone who already knows exactly which mix of rain and fire helps them will be happy here.