DVR provides an
NSURLSessionsubclass. When you try to make a request with the session, it will look for a prerecorded session. If one is found, it will play it back. If not, it will record it and then let you know you need to add the recording to your project.
This looks like a good replacement to Ruby's VCR.
Another library that looks interesting is Vinyl, which provides compatibility with DVR's cassettes. But given the reputation of Sam and Venmo, I will be trying DVR first and switching if it fails me.