Very cool! I was looking for something like this about a month ago when I was building an example web application for firmware developers. Firmware engineers aren't expected to know anything about databases and usually don't, so I just wanted some dumb JSON store in the cloud that didn't need any provisioning.
In the end, I went with Heroku and it's included PostgreSQL offering and stomached the complexity, but along the way I found https://jsonbox.io/, which I thought was neat and seems very similar.