mvn appengine:devserver
and navigate to
http://localhost:8080/
To have your browser updated after a change of a static resource run
livereloadx -l -p 35729 src/main/webapp/ --proxy http://localhost:8080/
install the livereload browser plugin and open your browser at
http://localhost:35729
If you want to look at your local datastore navigate to
http://localhost:8080/_ah/admin
after starting your development server.
After every successful commit the latest version will be deployed to
http://ncaleague-test.appspot.com/
If you plan to write a new client I suggest you experiment against this instance, rather than the "production" application.