After a lot of searching, I've just found some code suitable for use in my app to deal with the oAuth process, and it's working fine when I use my own client ID. But I'm missing something in the process because I don't understand how to (or why I need to) get a client ID for other users of my app.
Both the code I am using, and the example code on the Strava site, starts off with needing a client ID. But the code leads to the user being asked to log in to Strava - surely that process provides the API with the required client ID?
What am I misunderstanding here?