I have an app for which users have to authenticate. Now can I use the limit of 350 for every user (so when I have two users I can do 700 requests, if 350 for the one and 350 for the other) or still 350 for the whole app in total?
In API v1, yes the rate limit is per user/app combo – the context is “this user, using your application.”
Be sure and move to API v1.1 though, which has a very different rate limiting model.