As a Android developer I have developed near 10 apps for my employer and one app for me. I have used Google APIs, WCF Services, Rest API and all Local storage.
Play store https://play.google.com/store/apps/developer?id=Gunaseelan+Arumaikkannu
And I have added sample tutorials in http://v4all123.blogspot.in/
And also I tried video tutorials and added in https://www.youtube.com/channel/UCVNqmzyYdUbACmh15mL19iQ