If you are having issues with iOS and the Yi Home app following installation of app version 4.6 please add to this thread.
Include. Smartphone or tablet model, ios version and what the app is doing (I.e crashing after attempting to launch the app).
Include region you are in and try to delete and reinstall the app again.
If you are using Yi Hone have you tried Kami Home (using same credentials) and vice versa.