What I am using here to accomplish this assignement .
1.Afnetworking (https://github.com/AFNetworking/AFNetworking)
we are using afnetworking for network calls , because afnetworking bases on NSURLCache so we just need to set cache policy and it will provides us cachy automatticaly , we have set cache capcity and other params in appdelegate didfinish launching.and its very easy to add into new project with cocoa pods.
2.SDwebImage (https://github.com/rs/SDWebImage) Downloading image asynchoronioulsly we are using open source library SDWebImage https://github.com/rs/SDWebImage , Its image view category that provides the functionality to download image asynch and also provide web cachy as well , for the team purpose just need to call method with image view.
3 LIB OCMOCK (https://github.com/erikdoe/ocmock)
for testing using LIB OCMOCk