Quartz Composer has these features. You can zoom and also group components into a "patch" with its own set of inputs and outputs. I've had some success using Q

Quartz Composer has these features. You can zoom and also group components into a "patch" with its own set of inputs and outputs. I've had some success using QC for prototyping animations and custom UI controls for iOS, then later hand coding them in CoreGraphics. I got the idea from the Facebook devs who developed... I forget the name of the app. Anyway, would have been great if Quartz compositions were directly importable to iOS.