Use it or lose it

There are an amazing number of resources to maintain and enhance your android app development skills--

You could continue with the next 4 weeks of our coursera course

https://www.coursera.org/course/androidpart2

or go back to udacity--just look at the long list here--

https://www.udacity.com/courses/android

Remember, you've got to code and not just watch to learn from these MOOCs!