UniFi APs can be set up in standalone mode with the help of the UniFi Network mobile apps. https://help.ui.com/hc/en-us/articles/12594679474071-Standal...
'Log in to the UniFi Mobile App (iOS / Android)' ?
Log in to what? If they moved the 'cloud' requirement from the AP to the management app it doesn't mean they got rid of it.