If you have not heard, there are some free courses on Android on Coursera, and the first one started up a few days ago. The first week's assignments are not graded so you are not missing out if you didn't get in on the ground floor.
There are also two follow-on courses that'll start up later in the spring, running sequentially after the first Android course wraps up. If you went to Wash U in the 90s you may recognize the professor, Dr Doug Schmidt, formerly of the WU CS department.