It isn't clear from the website, but the GitHub repo states that this is for building apps for Pebble smart watches:
cloudpebble was the best part about Pebble - it made development so easy I did so much more of it
The developer experience for modern devices is so awful - the teams driving it are so immersed in big team development that they leak build systems, config, package management, certificates, permissions, and store integration concerns all over the place - then some of them have minor errors and you're stuck
Sometimes you just want to write a single file of code and have it run. Cloudpebble will probably be the thing that brings me back to pebble.
Nothing to install, no json to edit, no login req.. oh wait no, not that one..
I understand that you need an account to save/publish stuff on their servers, but I would really love a "guest mode" where I can just try it out, maybe even save to LocalStorage.
Exactly my thoughts.
"Forget about everything the gives you power and pay some rent to use this abstraction instead!!"
If this was the internet back when I started using a personal computer, I would put it down and do something else.
They publish local development tools too, this is just another option if you want it.