Hi Kai,
We do not send notification of when the device start to water or finish watering since that will be too many notifications and we do not spam the user.
However, We have implemented the app notification when the device starts to water. Currently it is ready for beta testing. If you are interested in trying this feature, 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