I've used Firebase as Database so you need to login with an email and NOT with just a name. This is made to use firebase and not to have a stand alone database, in the future, if u will need me, i can work with your api system.
Complete the fields with lenio@lenioapp.com - lenio to have correct access Any other user is rejected by the application
On login successfull the app will set a TOKEN encrypted (you will see the response).
live version http://www.gianlucasuarato.it/test/index.html