Most noise apps play a short recording on repeat. Over a night, you hear the loop.

Chroma generates its eight noise colors in real time, sample by sample, for as long as you leave it running. There is no recording and no loop point, so nothing ever comes round again.

GENERATED, NOT RECORDED

White, pink, brown, green, gray, amber, blue, purple and velvet. Each one is built from its own definition rather than sampled, so it is exact — and because it is generated, it costs no download and never repeats.

RECORDED SOUND, LEVEL MATCHED

Rain, a stream, wind, cicadas, a distant crowd, two ambient beds, and six birds — nightingale, robin, blackbird, chickadee, thrasher and wood pewee.

MIX UP TO THREE

Layer up to three sounds with an individual level for each. Rain under a drone. Wind behind crickets. Save a mix and return to it in one tap.

STOP WHEN YOU WANT TO

Set a wake-time.

BUILT FOR iOS

• A Control Center button — start and stop without opening the app

• Siri and Shortcuts, with the sound itself as a parameter

• Long-press the icon for your four most recent sounds

• Lock screen controls and artwork

• AirPlay and Bluetooth output, with the picker built in

• Three app icons

PRIVATE

No account. No sign-in. No analytics. Chroma has nothing to send anywhere, and collects nothing.

FREE AND PAID

All nine generated noise colors are free, one at a time, with the minute-based sleep timer.

One purchase unlocks the recordings, three-sound mixing, saved mixes, the wake-time fades and the alternate icons. It is a single payment, not a subscription, and it covers every device on your Apple Account.

contact: michael@mindfuljournals.org