NSTimer
, NSOperationQueue
, and almost all other APIs in the Foundation framework are available on both iOS and Mac OS X.
NSImageView
serves the same general purpose as UIImageView
and has similar API.
Animation APIs are a little bit different on the Mac; see Apple's Animation Overview for details.
There's no direct equivalent to UIGestureRecognizer
on the Mac; see this question for a start on implementing equivalent functionality.
The controller logic you might put in a UIViewController
subclass might go in any number of places in a Mac app, depending on what kind of app you're making and how you want its interface to work. Apple's Mac App Programming Guide is a good place to get started on how the Cocoa app/window/view architecture works.
I'd be a bit leery of Chameleon: for one thing, its GitHub hasn't seen activity in some time.