Uses

ComponentKit excels at powering list views with complex content. It was built to power Facebook's News Feed on iOS.

Simple and Declarative: Just like React itself. Why React? sums up these benefits.
Scroll Performance: All layout is performed on a background thread, ensuring the main thread isn't tied up measuring text. 60FPS is a breeze even for deep, complex layouts like Facebook's News Feed.
View Recycling: By requiring all view configurations to be expressed declaratively, ComponentKit makes error-free view recycling automatic.
Composability: By encouraging heavy use of composition, it's possible to build UIs as complex as News Feed without any single component exceeding 300 lines of code.

Interfaces that aren't lists or tables aren't ideally suited to ComponentKit since it is optimized to work well with a UICollectionView.
ComponentKit is fully native and compiled. React Native offers an alternative based on JavaScriptCore and React, including features like instant reload with no recompilation.
ComponentKit is built on Objective-C++. There is no easy way to interoperate with Swift since Swift cannot bridge to C++. Experimental projects like Few.swift or Katana are exploring how React's concepts could be applied in Swift.