Thanks for alerting me. Does the app show up at all, or does it disappear immediately after pressing the app icon? Can you share your phone's current iOS version & confirm that opening the app up in the App Store does not reveal an "UPDATE" button (but rather just an "OPEN" button)?
Finally, if in Settings, you search for Login to see the code, and open the "Analytics Data" page, you can search for Login to see the code here to see if there are any crash reports. If so, please consider e-mailing it to me at firstname.lastname@example.org.
Thanks so much!