Support

Questions, a reading that looks wrong, or something you would like added: write to us.

Contact

Email support@syncster.dev. For a reading you doubt, please say which device you have, roughly where you were and whether you were indoors.

Common questions

What does the accuracy mean?

It is the radius of the circle your device believes it is in: ±5 m means it is probably within five metres of the position shown. It comes from iOS, which works it out from the satellite signals and, where there are any, from Wi-Fi and mobile networks. Under an open sky it is usually a few metres; indoors it can be tens of metres or more.

Are the satellites shown the ones my iPhone is using?

No. iOS does not tell apps which satellites its receiver sees or uses. The app counts the navigation satellites that are more than 5° above your horizon, from their published orbits, your position and the time. Those are the ones a receiver under a clear sky can pick up. Indoors, or among tall buildings, your device hears fewer of them.

Why is the number so high?

There are four worldwide systems: GPS, GLONASS, Galileo and BeiDou, with about 150 satellites between them. Thirty or more are above any horizon at any time, and more over Asia, where BeiDou has extra satellites.

Does it work without the internet?

Yes. The compass, the accuracy and the position come from the device itself. The app carries a copy of the satellite orbits, and fetches a newer one from CelesTrak when you are online. The date of the orbits in use is on the screen, beside Orbit data. Orbits a few weeks old still give the right count, or very near it.

Why does the compass say magnetic north?

Until the device knows where it is, it can only give the direction from magnetic north. Once it has a position, the app shows true north.

The compass is off. What can I do?

Move away from magnets, speakers, cars and steel, and from cases with magnetic clasps, and turn the device in a figure of eight. The number after ± under the heading is how far off iOS thinks the compass may be.

It says location is off.

Open Settings, then Privacy & Security, then Location Services, then GPS Status, and choose While Using the App. For the best accuracy, turn Precise Location on as well.

Does it work on an iPad?

Yes. An iPad without mobile data has no satellite receiver, so its position comes from Wi-Fi and is less accurate; the accuracy shown says by how much.