I like the idea of User Management on the Mobile WebApp. Here are some thoughts that might improve it even more.
How about assigning ‘roles’ to users. What I would like is to assign a ‘ReadOnly’ role to a user, with or without a password, to be able to view the current operation but cannot change or run anything.
Then perhaps a user that has limited access, like your garden service, to run a predefined program or to run stations manually. If, for this user role, you allow manual operation then you, as Super-User, have to set upper limits for the stations to run. You don’t want the garden service to run a station with a ‘0’ timeout.
Summary:
ReadOnly or Guest access role to view operation only.
Limited-User role with predefined access.
Super-User role that can do everything.
Ingo