That’s really cool! The Dash buttons work really well for the stationary use case (and have the benefit of being virtually cost-free if you actually use them for the Amazon-intended purpose once!) but having them to be in a given WiFi limits their use cases outside your home, so that’s cool to see (and 
for maximum privacy in the 1-Button!)
Looking forward to hear more about them in the future and I’ll let you know if I come up with an idea where I want to try one!
ps. I think such a device could have many fans among field-working biologists. Back in my days we often had to track some binary observation in the field and you had to do it manually with pencil & paper. This would have been a blessing back then 