The Icon App allows you to share access to the system:
Press the three lines in the upper left corner of the main screen
Choose [Settings]
Press [Share house] to open a page that will show you a code
The code will for security reason only be valid for two minutes
The person receiving the code should press [Receive house] in the App and type in the code from the sender within two minutes
Note: When sharing a “House” you also transfer full rights to install or delete thermostats. You can, however, choose whether you want to also transfer rights to add or delete other users.