Thought some might be interested in the tech stack:
The Editor and Dashboard are built with Ember.js, which we love.
Rails on the backend, with Postgres and Redis.
We get a little help from Pusher, Transloadit and URL2PNG. The Android and iOS apps are PhoneGap with an Ember app inside.
Feel free to ask questions about our experience with any of the above.
Happy to share.
If you're building an app maker and not just an event app creator, I might assume you're shipping JS code and storing in the db or something along those lines. My question is, how much of your code is bundled with the app in the store and how much of it is fetched and eval'd at install/run time?