A demo project consisting multiple RxJava examples that could be shown while talking on RxJava I (Rivu Chakraborty) used this project to demonstrate some of the RxJava functionalities, while on a talk about RxJava, organised by Google Developer Group Kolkata on 11/11/2017 You may also have a look at the Android Project I used at the same workshop https://github.com/RivuChk/NotesApp.
I may also use it for another Workshop on Reactive Programming in Java organised by Facebook Developer Circle Kolkata