My iPad is as up to date as Apple will allow it to be (Bless Apple for their commitment to backward compatibility!). It runs IOS 10
I reinstalled the app from the appstore using the option ‘install latest version compatible with your device’ (Version 1.8.0).
The same iPad runs the full Ring app (5.29.1) and that works adequately.
the iPad is used solely as a monitor for my Ring Video Camera Pro and has worked since installation around 9-10 months ago.
Regards
John