Does force quitting an app affect GPS tracking on iPhone?

The short answer

Force quitting an app stops it from recording your GPS track. Locking the screen or opening another app while a route is recording does not — iOS keeps a location-tracking app alive in the background for exactly that reason. Swiping the app away in the app switcher is a different kind of instruction: it tells iOS to end the app's process completely, and a process that no longer exists cannot keep logging position fixes, no matter what permission it was granted beforehand.

Backgrounding and force quitting are not the same thing

A phone spends most of a walk with a GPS app backgrounded — screen off, or another app like a camera or a map open in front of it. iOS supports this on purpose: an app with permission to use location in the background can keep receiving position updates the whole time, which is the entire point of a route recorder that does not need to stay open on screen. Nothing about locking the phone or checking a message mid-hike interrupts that.

Force quitting is a separate, deliberate action, and iOS treats it as one. Swiping an app up and away in the app switcher is read as the user explicitly asking the system to shut that app down, not merely step away from it for a while. Once iOS acts on that, the background permission that was keeping the app alive stops mattering, because there is no running process left for it to apply to.

What actually happens when you swipe an app away

The app's process is terminated. Whatever it was doing at that instant — including receiving GPS updates — stops immediately, in the same way any other running task on the phone would stop if its process were killed. iOS does not treat a location-tracking app as a special case here; force quitting ends it exactly as it would end a game, a browser tab, or anything else in the switcher.

This is different from what happens when iOS itself decides to end a background app to free up memory, which can also happen without any GPS app crashing or misbehaving. The distinction between the two rarely matters for the end result — both stop the app from running — but only one of them was something you actually chose to do.

What happens to the track you had already recorded

That depends entirely on how the app in question handles the points it has already logged, not on anything iOS does. An app that only keeps a route in memory while it runs loses everything the moment its process ends, since there is nowhere else for that data to have gone. An app that writes points to storage as the hike happens keeps whatever was saved up to that point, even though nothing further gets added after the process is killed.

This is worth knowing before it happens on a real hike, not after, since there is no way to ask an already-terminated app how it handled the data it was holding.

Things that trip people up

• Assuming any interruption stops a GPS track the same way — locking the screen and switching apps do not; force quitting does. Treating them as equivalent leads to force quitting apps out of habit and losing a track that would otherwise have kept running fine.
• Blaming the app for a track that stopped after a swipe-away — that is iOS acting on an explicit instruction to end the process, not a bug in the app.
• Force quitting a tracking app to try to save battery mid-hike — this does stop the GPS track, since it ends the very process doing the recording. It is not a way to pause tracking; it is a way to end it.
• Expecting a track to keep recording after force quitting because the phone still shows the app icon on the home screen — the icon staying put has nothing to do with whether the process behind it is still running.

Where TrailCam fits in

If TrailCam is ever interrupted mid-walk — including by a force quit — it offers the unfinished route back to you the next time you open it, rather than treating the partial recording as gone. GPS route recording itself keeps going through a locked screen or another app in the foreground; only ending the app's process actually stops it. TrailCam is free to download.