Each hub has a single username and password. This means it needs they need to be set to something that the user owner of the system is happy to give out to anyone who they want to be able to control their the heating.
If two people are logged on at the same time, this is fine, but they will find that they can override each other's settings if they are adjusting the same room at the same time.
The Genius Hub will take the last command that it receives from any of the apps that are logged into it.
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