Ok, I've put my arduboy web server into publishable shape. Mostly. You can find it on github.
It uses the heroku SAS platform. You can publish a few low-usage applications on it free, and this works fine there. See the github repo for details on usage.
There's a small test app that creates arduboy files based on the configuration dictionaries. It would be straightforward to change that to input an arduboy info.json instead. I'm just not sure how useful it would be.