I was using it but it was very unreliable in my experience. The PWA app you can install on your phone would work for a few days and just appear to stop working until you reinstalled it. Then with Mozilla firing devs including the devs who work on their core product (Firefox/Browser Engine) and then spinning WebThings out into it's own thing, I have decided to stop using it because I don't believe it has much of a future because the management appears to have gone off the rails.

I will reevaluate it in a year, if it still exists, because it's actually a pretty nice platform to use.