Seems like I saw online that Netro is beta testing an app that does this. I wasn't looking for that, so I didn't really pay too much attention to it. You might do a search using different key words. Support asked the person if they would to be a beta tester.

Hi Petro, 

We have implemented the app notification when the device starts to water. Currently it is ready for beta testing. Please let us know if you are interested in trying this feature and if yes we will enable it internally for you. In the next app release there will be a public on/off control for this feature. 

Thanks, 

Netro Support