Google Developer Advocates Reto Meier, Dan Galpin, and Katherine Kuan will give you step-by-step training for how to build an Android app, as well as best practices of mobile development in general and Android development in particular. With that developer will also give you feedback and guidance between the course.
Google making this online classes to those who have programming knowledge but didn't familiar with the Google mobile operating system. Frequently Google helps world wide users, specially student to give free online education classes or guidance with its team.
The free course of Udacity contains Theory, Videos tutorials quizzes and support forums . All you have to note that to avail the above course for free, you should get it by selection 'View Course' on this page. The free course will be valid for two weeks and then will cost you $150 per month for the guidance.
Note- The course material is available for free but the guidance is paid.