title: Check which user is currently using the app
body: <p>I have two types of users for my app,Staff and Student. I am using firebase auth to authenticate these users. They have separate login pages and their data are stored in different Childs of the database. If the user is a student she shall not be able to use some features of the app that are specific to the Staff. Is there any way to check which user is currently logged in so that I can manipulate the features of my app accordingly?
  Ps: I am using email and password login</p>
  
  <p><a href="https://i.stack.imgur.com/JI7n6.png" rel="nofollow noreferrer">Database</a></p>