Add my wifes iPhone

I have my system in working fine. What I would like to is add my wife’s phone, started last night but quit when it wanted to flash up. I did not want to screw up what I already have. In other words can the system be controlled from two devices?

Just add your username and password to the app on her phone. I’ve got it working on multiple devices.

Thanks I’ll try that when I get home tonight.