Thanks for the tag
@Antje77
I don't use Libre any more and never had an iPhone.
I used to use xDrip+ on my Android phone and have read that Shuggah is the equivalent on iPhone.
Like Diabox, the best place for information about xDrip+ is facebook. It is a closed group but they seem to let in everyone.
The Facebok account includes downloads (including the app because it is not available on the playstore) and seems to be supported by the developers.
@DEBBIESCOTT seems to use Shuggah so may be able to direct you to information about that.