There are two Garmin apps. One does everything the watch can, the other does as little as possible — to save battery. Both get their information from the phone, never from an account of their own.
| Geo-Harbor | Eternity | |
|---|---|---|
| Watch GPS | On, continuously | Never |
| Reports your position | Yes, every 30 seconds | No |
| Fetches data | Continuously | Only while you look at the page |
| Distance measured from | The watch's own position | The phone's latest position |
| Battery use | Noticeable | Almost none |
| Suits you when | You want the group to see you without the phone out | You want to see the group but save battery |
The watch has neither an account nor a login of its own. Everything goes through the phone and the Geo-Harbor server.
The watch shows a code. You enter it in the phone app, and the watch receives the phone's identity. That is the only thing stored on the watch.
The watch asks the server which group the phone is in — every time, before fetching anything else. No group is stored on the watch, so if you switch group on the phone the watch follows.
The server replies with the group's members and their latest positions. Your own row is included, and that is the position Eternity measures distances from.
Wind is fetched from Geo-Harbor's weather proxy for that position.
The Eternity app can therefore show how far away your group members are without the watch ever searching for satellites. The trade-off is that markers land where the phone is, not where the watch is — which is stated in the app itself.