I am a big fan of Rachio controller and I ended up being the Rachio expert in our neighborhood to help neighbors configure their devices correctly.
I have more than half dozen Rachios shared with my account. As most of the homes came with sprinkler systems preinstalled, it is not economical to add in a flow sensor. So I help them configure precipitation rate for each zone by creating custom nozzles. What I found is that Rachio iPhone app (and Web app too) don't let me create custom nozzles for a selected device (i.e. shared device). It lets me create custom nozzles for my controller, but not the one shared with me. I wonder why.
Please enhance this and let me help you sell dozen more Rachios!