Earthquake early-warning alarms now sound even when your phone is on silent. For strong shaking, a countdown opens over your lock screen with a live map of the wave heading your way. Warning time depends on your distance from the epicenter; very close to it there may be none.

New: a Notifications page in Settings keeps your past alerts, including how many seconds of warning you had.

Redesigned device setup, with clearer Wi-Fi steps and signal strength.