The Cocoa Touch layer contains key frameworks for building iOS apps. These frameworks define the appearance of your app. They also provide the basic app infrastructure and support for key technologies such as multitasking, touch-based input, push notifications, and many high-level system services.

The Aura project centers around a collection of high-quality, well-tested, semantically versioned, standards-compliant, independent library packages that can be used in any codebase.

Trailblazer is a thin layer on top of Rails. It gently enforces encapsulation, an intuitive code structure and gives you an object-oriented architecture. In a nutshell: Trailblazer makes you write logicless models that purely act as data objects, don't contain callbacks, nested attributes, validations or domain logic. It removes bulky controllers and strong_parameters by supplying additional layers to hold that code and completely replaces helpers.