I’ve been experimenting with GPSLogger rather than Overland to upload GPS tracks from my phone, but I can’t get it to work reliable when it can’t access the API. It seems fine when it has no network access at all, but if it has any then it assumes it’ll have API access and seems to throw data away when it sends into the void. Overland is simpler and so far more reliable. It’s only downside is that the Android version doesn’t seem actively maintained.