If you have multiple tanks with Mobius devices or want to have control of them while not having to be right next to the tank, it's really good. Other than that, it's not at all a necessity as it currently stands right now feature-wise.
I honestly don't understand how Ecotech can make all this great equipment and then decide to not support wifi connectivity on their mobius devices, and then have a buggy app on top of that. Compare that to Red Sea equipment that connects to wifi out of the box and actually has a working app that is streamlined and has a user-friendly UI.