Likewise. This is for my wife who is the diabetic but I'm the tech support

so here are some clarifications for the less techie!!!
Important to delete the app first from the iPhone.
Librelink app should be listed in Purchased Apps with the cloud download symbol on the right. If instead it says "open" in the Purchased Apps then it has not been deleted, in which case go back to the home screen and delete the app. Click cloud symbol to start installation.
On opening the app it had an option to Sign In to an existing Libreview.com account which I did straight away, and then still had to go through "first time" set up stuff
It did not seem to scan the sensor until I followed its instructions to tap the radiating arcs icon at top right of
app screen (not the overall phone screen) then when brought up to the sensor it downloaded the last few hours and current blood sugar level. Also knows the sensor end date ok.
It also now seems to be reading the sensor continuously without scanning.
I think readings are still being sent to the libreview.com account ok.
Seems to me that the app basically works ok but
only from a fresh install. Thus historical librelink data on your phone is lost and probably needs to be lost for the updated app to work. Still better than reverting to finger pricks.