To run, create local.properties
file with:
sdk.dir=LinkToYourAndroidSdk
In Mac it should be:
sdk.dir=/Users/<your_user_name>/Library/Android/sdk
Presentation explaining this project:
https://docs.google.com/presentation/d/1G10q-ciyAEEb3iHB49ywZZP4IM67VOgQdUlUQm8Wbis/edit?usp=sharing
For help in introducing data persistence, great thanks to @jgarin