I've been playing with Framer as a UI designer recently, and it's really awesome. For those not familiar, the concept is that in addition to the two editing modes in the Pythonista UI editor (the right bar with properties and the drag'n'drop interface on the left), Framer also has a third pane which is a code editor. As you move elements around or change properties, it's reflected in realtime in code (CoffeeScript in this case).

This is an awesome tool, it works very well and makes prototyping and animation design really easy. Something similar for Pythonista would be neat. Just a thought. Maybe I'll try to build it :O

