Last week's Ember NYC Meetup introduced a number of new things into the Ember world. One of which is Ember Twiddle.
It's long been quite tedious to demo Ember apps and features on jsfiddle or jsbin. Ember Twiddle is now trying to make this easier by allowing you to create and manage an entire Ember app in a simple split-screen web editor.
Ember Twiddle is currently limited to running Ember 1.13. Twiddles can be saved as a gist on Github and shared with other people. Ember Inspector currently seems to have an issue finding the Ember app that is rendered in the iframe.
The code is of course open source: https://github.com/ember-cli/ember-twiddle
If you haven't done already, watch the Ember NYC recording on YouTube.