Google’s Material Design – Official Guidelines
Make sure to check out these guidelines before you start designing an Android app, to ensure a good user experience and ease the development process.
Color Safe – A Tool for Matching Perfectly Readable Colors
A powerful color matcher and calculator for text and background contrast ratios, based on WCAG Guidelines.
Really Good Emails
A good user experience stands in the small details. Here is a large collection of good product email design code (that came into our inbox).
Why San Francisco
For all the type nerds and Apple fans in the world: an in-depth article about Apple’s San Francisco typeface. By Nick Keppol
The iOS Design Guidelines
Very easy to use, straightforward iOS Design Guidelines that follow the official HIG for iOS by Apple by Ivo Mynttinen. Learn the rules, so you know how to break them.