Flysystem - a filesystem abstraction which allows you to swap a local filesystem with a remote one. That could be very useful for assets manipulation system in CMS or something.
Note
Mobile-Detect - a lightweight PHP class for detecting mobile devices. Works like $detect->isMobile() etc., very handy for choosing a frontend rendering strategy based on this info.
в MobiDev (Харьков, Украина)
Code in Ruby and Elixir, but still love PHP. Explore ES6 and Vue.js. Explore databases, use Ubuntu and MacOS, think about IT people and management
Заметки
libphonenumber for PHP - a library for parsing, formatting, storing and validating international phone numbers.
Geocoding PHP library with a huge set of geocoding services abstraction.
Firefox Nightly (version 29) supports CSS variables. Okay, now give native CSS inheritance and I will be happy :)
Antonio Ramirez has shared a guide how to add FontAwesome via Composer in Yii2 project as Asset Bundle.