Not CSS. Instead of trying to force UIKit to fit CSS syntax, properties, conventions and constructs. Classy is a stylesheet system built from the ground up to work in harmony with UIKit. It borrows the best ideas from CSS and introduces new syntax, conventions and constructs where appropriate.
Handy keyboard shortcuts for the iOS simulator. Find all tapable views and activate them with a shortcode - Inspired by vimium. Escape out of UITextFields/UITextViews. Scroll using the arrow keys.
Masonry is a light-weight layout framework which wraps AutoLayout with a nicer syntax. Masonry has its own layout DSL which provides a chainable way of describing your NSLayoutConstraints which results in layout code which is more concise and readable. Masonry supports iOS and Mac OSX.