title: Anonymous auth by firebase
body: <p>My app need to have the simplest type of auth. I dont want to ask from user any FB or google accounts, cell phone number even email address. User just need to register with login and password.</p>
  
  <p>I have found anonymous auth by firebase. But there is a key which can expired.</p>
  
  <p>I need user just register with log+pass and after that stay loged in while the app installed.</p>