I read my RuuviTags with an iPhone and several Android devices. I noticed an interesting difference between the iOS and Android apps, regarding the length of the log history:
iOS seems to store everything and forget nothing, but the App always shows 10 days of history. When I upload the data, it takes a long time if one has used the RuuviTag for a long time. The App does not have any settings regarding the history duration
Andoid seems to store and show at most 10 days of history (I have the history setting to 10 days). The App displays 1-10 days of history, depending on the setting, but always uploads (and stores?) 10 days of history
It would be nice to have an alignment between iOS and Android. Here is my wishlist
User-defined history display (also for iOS)
User-defined history delete (neither automatic as in Android nor all-or-nothing as in iOS)
iOS must prune the data in background, and should be able to do it if you don’t kill the app forcibly.
It’s very interesting why are you reporting that iOS doesn’t prune data at all. Could you please share your iOS version and app version? Are you killing the app manually?