Thanks for asking!
I’m not sure how others have done it, you might want to check with others who have written similar Solid apps, for example I think @SharonStrats and @labra.
Also, if there’s a conflict between making a great app and proving the usefulness of Generative Objects for Solid, you should probably go with the latter, but thats just my opinion.
so fwiw anyway here’s my thinking…
The app saves location info and time every so often in the user’s (I’ll call it the traveller’s) pod automatically, and during those times when the location is changing fast then maybe that data is saved more often. The user can choose to pause or stop the location tracking anytime. The user can also cause that data to be saved on command for important points of interest. Saving it at a point of interest might leave the pause/continue toggle the same or not, depending on user configuration. The user can link any point on their route to any resource on their pod (i.e. pictures, etc).
I agree that all that data should be stored in the traveller’s own pod. Others authorized by the traveller can only read it. I also agree that anyone else’s artifacts about a point of interest (pictures, video, audio, text) should be stored on their pod and they and the traveller (or others) would have to agree for those things to be visible.
I also agree that separate lists of friends/family/others would be needed, separate from the friends list in the pod, because the list for this app would change a lot and may sometimes include some who are only temporary friends who want to coordinate routes. Inviting the traveller’s pod friends may be too many invitations or sometimes not appropriate. A configurable list of lists may be necessary, say one for work friends meeting for lunch, one for family members on a shopping trip, another for coordinating a sales meeting with customers.
Hope this helps. I’m looking forward to seeing the app!