I can't say that this would be warranted for a single betta tank since the risk of disaster is fairly low in a small/lightly stocked tank. However, for community tanks full of expensive fish or if you are prone to changing water conditions or power outages this might be worth it. It will send you a text if your tank goes wonky!
Wow. This thing is wonderful, if it works as advertised. I wonder how accurate it is? Not having to bother with those liquid test kits would be amazing. Imagine being able to keep such a close eye on a tank while it's cycling!
I have a good long timeline before the 75 gallon is ready to fill. Maybe there will be some reviews by then.
Admittedly, I find shaking a test tube and shouting "FOR SCIENCE!" to be amusing, but not that fun, at the end of the day.