title: magic links, how do they work
body: <p>Some mobile apps, notably <a href="https://auth0.com/blog/2015/12/04/how-to-implement-slack-like-login-on-ios-with-auth0/" rel="noreferrer">Slack</a>, are using magic urls for authentication. I'm having some trouble finding resources on implementation, and most importantly, whether android has a similar method for this. </p>
  
  <p>My understanding is that the server would issue an e-mail with this magic link (something along the lines of <code>app://gf234h23f4j234342342</code>), the link will then be passed on to a registered <code>app</code>, which could then use this information to contact the server to get information on the user. Is this correct? If so, gmail seems to have issues recognizing this as a url, how is this resolved?</p>