A guard without eyes and ears
In the “Alarm system” role a phone uses neither camera nor microphone. It relies on motion sensor, position and GPS. A cheap second phone in a backpack, a bike basket, a suitcase or a glovebox becomes a guard that raises the alarm when someone touches it.
Armed, siren, notification
You arm the system and have a short grace period in which you can walk away. If the phone is then moved, lifted or unplugged from the charging cable, a shrill siren sounds and everyone in the household gets the notification. The siren runs on the phone itself and needs no network. From a distance you can also trigger the siren by hand to find a phone nearby.
The map
The phone reports its position, more often while moving, less often at rest. In the viewer you see the track on a map with markers for start, armed, disarmed, alert and standstill. The track is stored for up to 14 days and at most 6,000 points, and can be downloaded as a GPX file, opened in Google Maps or deleted at any time. The map data comes from OpenStreetMap.
When the connection drops
If an armed system stays offline for longer, the server itself reports “Alarm system offline”. That can be a phone that is switched off, airplane mode or a missing network.
How many devices
Up to five alarm systems and phones are possible per account. Each has its own name, its own map and its own settings for triggers and responses.
The honest limits
Switching off, airplane mode, an empty battery and force-quitting the app cannot be prevented on Android. GPS indoors is inaccurate. And an alarm system is no substitute for a lock; it can only buy time and provide clues.