I also purchased the Valve Monitoring App before I read that each controller needs a separate App… or another $30! Since I have two controllers, that can not be combined at the same address, I now have one controller with the Valve Monitoring on three valves and the remaining valves on the 12 station controller with no Monitoring App, as I am not sure I want to spend another $30. I wish this information was included on the ad sent on the internet. With this exception, I have been very happy with my Rachio Controllers!
