Quick answers below. Anything else, just write.
Tap the round You button on Home, then Back up. Save the file somewhere you'll find it: Files, iCloud Drive, or AirDrop it to yourself. On the new phone, open You, tap Restore, and pick that file. Restoring replaces what's on that phone. Keep has no account, so a backup is the only way to carry your sky over.
Touch and hold your Home Screen or Lock Screen, tap Edit then Add Widget, and search for Keep. "Tonight's star" shows one moment from your Keep list. Tap it to open your list. It needs Keep 1.1 or later.
After five rounds, Keep looks at what you catch fastest, the stars your thumb reaches for before you think. That why becomes your sign, like The Hearth or The Compass. It can change as you play.
Once a day everyone gets the same stars. Catch your five, then send your sky to a friend. They play the same drop and see how close your skies land. A new drop arrives at midnight, your time. You can turn on a daily reminder in settings.
Yes. Open You, then Your stars. They fall in your drops, mixed in with the rest, and stay on your phone. Nobody else sees them.
Only anonymous counts of which moments get kept, plus, if you use Match or Circles, your sky and the star name you picked, with those friends. No account, and Keep never asks for your name. To delete what's on our server, open You and tap Delete my data from Keep's server. See the privacy policy.