On iOS, I’m using Galileo Pro, and testing TraceMyTrack.
GalileoPro is quite stable (meaning, it’s resilient to being shutdown while in background), but still crashes from distant time to time, leaving gaps in the recording.
TraceMyTrack is looking promising as it recovers from being shutdown while in background and keeps on recording.
I use both, and a Garmin Quest GPS (never crashes, but satellite reception is worse) to save tracks and later merge them before use. I use the tracks simply to geolocate my camera photos.
All Mapillary photos are taken with the app, so no problem there with location (except when Mapillary fails to fetch the location for the first few photos in a sequence and I need to add it manually…).