It's also very easy to edit some basic data through the app so if you notice an error in the map it's usually possible to fix it right there and then.
How so? GPS is like FM radio: you send nothing, you only receive.
Apps like organic maps or comaps let you use the maps fully offline and you can compute itineraries without GPS when your need this (from point A to point B, with as many stops as you wish).
I strongly recommend you to seriously look into comaps or organic maps if you don't know them.
Now, "GPS isn't working or depletes my battery, what do I do?" is an interesting topic worth looking into. It seems you are trying to automate what we all do when GPS doesn't work well. I find that relatively easy in a city, not so much in a road on the countryside.
That's not really GPS anymore so when discussing the topic it would be worth being exact on this.
I frequently use it in the airplane without WiFi and wish to have high definition, but downloading country by country is too cumbersome.
Do there exist apps that share their offline map data? As in: install app A, dowload offline map data for country xyz, use in app A, install app B, use same map data in app B (or C, D etc) without re-downloading the map data?
As I understood, that was not the case as each app uses its own format which is some underlying public geo info (presumably too big to have on device), filtered / processed in per-app fashion.
The sillyness & waste of this is obvious. So: any progress in resolving this situation?
Until you realise that there is not one true way to show a map, and that different apps may actually have different needs. Suddenly it becomes obvious that not all apps can use the same shared offline data.
I make changes to OSM so they can be propagated to a cycling-specific mapping tool I use (it's a commercial tool with their own custom map layers) - it takes about 3-4 weeks from when a change is made on OSM for it to be incorporated into their data set.
So yeah, it's not as simple as "we all use OSM so we'll just share all our rendered mapping values".
Users could pick & choose what subset(s) of map data they want to store locally. Different apps could pick & choose what features to offer, how to use available data & how to render it.
Sad to see that such a conceptually simple problem hasn't been addressed yet. We're talking a good # of apps here, many millions of users, and enormous amounts of storage & bandwidth wasted.
Edit: I'm assuming that last bit is a problem for the app developers themselves, too.
We ended up taking screen shots of Google Maps where we zoomed in on local streets, on an ad hoc type atlas. I wish we had this app back then
Maybe the data could be shared/distributed via hypercore or similar.
I find heatmaps are my primary way of finding new mountain biking trails and routes.
Edit: hmmm I don't think I understand that wiki. Most of those are not the type of heatmap I was thinking of. I'll keep looking into it though.
Here's a link that has traces enabled (aka layer "G"): https://www.openstreetmap.org/#map=15/52.47166/13.40590&laye...
There's also a list of recent uploaded traces: https://www.openstreetmap.org/traces