Songbird Alarm

What if the morning didn't have to start with a loud noise?

Songbird Alarm starts forest birdsong at a volume you can barely hear, then raises it over about 15 minutes. While you sleep deeply, a quiet sound will not wake you. As your sleep grows lighter, you notice it. At the end, the clear voice of the Japanese bush warbler sings.

Every sound was recorded by hand in the mountains of Gifu, Japan, with equipment that reaches frequencies a phone cannot and wooden boxes the recordist left in the hills: more than a hundred recording sessions.

■ The forest, from the moment you lie down

To fall asleep to: Midnight forest, Rainy night or Bell crickets. Each plays very quietly all night; you can turn the screen off and leave the phone locked.

■ For the mornings you don't wake up

There is a backup for when the quiet sound isn't enough: about 15 minutes in, the bush warbler calls clearly. If the app could not make a sound at all - force-quit, media volume at 0% - the iPhone's own alarm rings instead, with vibration. If the warbler did sound, that Backup alarm cancels itself. On the days you choose, it also wakes you on a morning you forgot to press "Good night".

■ Your mornings, written down

When it began ringing, and how many minutes until you got up. Which sound you woke to most easily. Your waking time by day of the week, how it sits against sunrise, roughly how long you slept - all of it stays inside your iPhone only, never sent anywhere. Tap the Night Ring in the Wake log and the night opens large: The shape of last night. Sunset to sunrise, the time in bed and when your iPhone moved are laid over one 24-hour ring. "Previous night" goes back through earlier nights.

■ Last night's sounds - speak a night-time idea into a note

A thought that comes in the night is gone by morning, and turning on a light wakes you. Say it out loud instead, clearly, eyes closed. In the morning you can read it as text - the feature the maker wanted most. Between "Good night" and the morning, the iPhone records a short piece only when a sound clearly louder than the room's usual quiet is heard - at most 60 seconds each, at most 90 minutes a night. You can listen back in the morning. A recording with a human voice in it can become text, in the language your iPhone is set to. Recordings stay inside this iPhone only and never reach the developer. You can turn the feature off in Settings.

■ Season Bookmarks - the season changes its name every five days

Discovery signals