This is an adoption of the Reactive Programming JavaScript tutorial (code), but focused at RxJava. A number of exercises have been 'implemented' in this project. I tried to mirror the behaviour of the learnrx tutorial, in which you can just open up an exercise, and try to complete it.
To do this, open either an interactive or a non-interactive exercise, and complete one of the answers. The non-interactive exercises all have unit tests, so mistakes can be detected in a timely manner. In case you want to see the solution of an exercise, open up the solutions class. I tried to implement a solution as close to the original JavaScript implementation as I could.
Some exercises contain a short summary on what the assignment is, but for the complete story or for more details, one can always look at the original tutorial.
To learn more about RxJava or its operators you should head over to their wiki, which contains excellent documentation and marble diagrams on how RxJava works. As for Rx itself, Introduction to Rx is an excellent resource.