Use the Safari Services framework to integrate Safari behaviors into your iOS app.

The Firebase iOS framework for adding realtime data synchronization to your app.

A collection of source from different Google projects that may be of use to developers working other iOS or OS X projects.

GTMSessionFetcher makes it easy for Cocoa applications to perform http operations. The fetcher is implemented as a wrapper on NSURLSession, so its behavior is asynchronous and uses operating-system settings on iOS and Mac OS X.

Render advanced 3D graphics and perform data-parallel computations. Get fine-grained access to the GPU while minimizing CPU overhead. The Metal Framework provides extremely low-overhead access to the GPU, enabling incredibly high performance for your sophisticated graphics rendering and computational tasks. Metal eliminates many performance bottlenecks—such as costly state validation—that are found in traditional graphics APIs. Metal moves all expensive state translation and compilation operations out of the critical path of your most performance sensitive rendering code. It provides precompiled shaders, state objects, and explicit command scheduling to ensure that your application achieves the highest possible performance and efficiency. Graphics, compute, and blit commands can be used together seamlessly and efficiently. Metal is specifically designed to exploit modern architectural considerations, such as multiprocessing and shared memory, to make it easy to parallelize the creation of GPU commands.

Nanopb - protocol buffers with small code size

Protocol Buffers (a.k.a., protobuf) are Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data.