JavascriptCore is a framework that offers the ability for a iOS application to interact with javascript code. Primarily used for cross platform code sharing, it can also be used to extend a iOS application with macro capabilities. This framework offers a world of possibilities for extending any iOS application.
This is the source code for a demo application that is described in the blog article How To Example: Extend a iOS Using JavascriptCore As A Macro Engine
Rodger Higgins is the founder of Spazstik Software, LLC. He has created StackCalc, The Visual Touch Calculator and SPZTracker.