AngularJS is becoming more and more the default for web-based mobile apps (aka the Hybrid app). Frameworks like Ionic Framework and AppGyver Steroids use it as the glue that makes up the Single Page Application (SPA) structure.
It always takes some effort to find the best resources to teach yourself a new technology. Recently I made very good use of Thinkster.IO to teach me AngularJS.
Thinkster.io uses books, online sources (like blogs) and has a clear teaching path with checklist (create a free account to keep track of your progress) so you can endulge into a full-blown learning path for one of the developer topics.
Check out their free AngularJS tutorial roadmap at https://thinkster.io/angulartutorial/a-better-way-to-learn-angularjs/ and get your coding groove on!