Lethe Noise

Brown, pink and white noise, each on its own slider. Brown is the default.

Auto Mix raises pink over the brown in slow swells, and turns itself off when you adjust a noise slider. If everything is at zero, it brings the brown up first.

The sleep timer runs for 15, 30 or 60 minutes, fades out over the last three, and stops.

The drone is made of five families: a harmonic bed, a set of singing bowls, an overtone field, a beating cluster, and gestures (occasional bells, plucks, sweeps, hums, breaths and strobes). Each has a level and a few controls of its own.

It is not a sleep aid. Some of it is calm and some of it is strange. Headphones help, since much of the movement is in the stereo field.

A scene pairs two families with a reverb setting. Each one moves slowly between three versions of itself over about fifteen minutes, and the sliders move with it. Adjusting a control makes that control manual; the rest of the scene continues. Hold stops the scene where it is without stopping the sound.

Vigil

The harmonic bed with gestures. In the first version of the app, this was the whole drone.

Temple

Singing bowls over a low overtone field, in a long, bright reverb.

Glass

The overtone field over the beating cluster, with the brightest reverb and a slowly swelling harmonic halo.

Transmission

Pulse Grid over the beating cluster. No reverb.

Drift

Temple, then Glass, then Vigil, over about twenty minutes. This is the default.

Two pieces that are not drones: Pulse Grid, a dry rhythmic piece after Ryoji Ikeda, and Chord Cloud, a generative chord progression with a harp-like figure over it.

• Works offline. No account, advertising, built-in tracking or recordings.
• Keeps playing with the screen locked, with the usual lock-screen controls.
• Pauses when headphones disconnect, instead of switching to the speaker.
• iPhone and iPad, iOS 17 or later.
• In beta on TestFlight. There is no public download yet.

Questions and bug reports: support.