Anchor Alert

An anchor alarm for iPhone. Mark the anchor, set a circle, and go to sleep: if the boat drags out of it, the phone rings. This is the beta. It works, it isn't finished, and we'd like to hear what you think.

The map with the anchor marked and the watch holding — Holding, all night

The alarm ringing after the boat dragged — It rings when you drag

The Systems Check — It says when it can't do its job

The Live Activity in Notification Center — On the Lock Screen

What it does

Mark the anchor, set the radius. One tap marks where the boat is; plus and minus set the circle. Slide to arm the alarm.
Rings on the boat. The siren is on this phone, with no network, no account and no server in the way. It plays through silent mode and Focus as a critical alert.
Doesn't cry wolf. A fix or two outside the circle isn't a drag. The alarm waits until most recent fixes are out, over a window that grows when GPS is poor.
Says what it doesn't know. The Systems Check watches GPS, permissions, the volume, the battery and whether the app is still running, and says plainly when the watch can't be trusted, rather than guessing.
Glanceable at 3 a.m. The distance and the verdict on the Lock Screen and in the Dynamic Island.
Every anchorage written down. The Log keeps each night: the track, the alarms, the radius changes, as a replay and a GPX file.
Anchor Alert Remote, optional: a web page and email or text alerts for someone ashore. The boat never waits on it.

As the app says on its last onboarding page: Anchor Alert is an aid, not a replacement for proper seamanship and a careful anchor watch. GPS accuracy, battery life and signal loss can all affect alerts.

What to test. Anchor somewhere you know, mark it, arm it and leave the phone below deck overnight. In the morning, open the Log and see whether the track looks like your swing. Turn on Airplane Mode and check it still holds. Walk the phone up the dock past the radius and check it rings, loud, with the phone locked. Take a screenshot in TestFlight and send it with your note, or email contact@onnav.com.

Look closer

Screens: every screen, and what each part does.
Palette: what each colour means, and how well it reads.
Design System: the rules every screen follows, and where the app breaks them.