title: How does Twitter for iPhone bookmarklet work?
body: <p>Twitter client (formerly Tweetie) allows you to define a bookmarklet in Safari that launches the app. I want to know which iPhone API allows you to register the protocol specifier (or whatever it's called) - in this case "tweetie:" - in order for this bookmarklet to work.</p>
  
  <p>The instructions can be found <a href="http://www.atebits.com/___?javascript:window.location=%27tweetie:%27+window.location" rel="nofollow noreferrer">here</a> and the bookmarklet itself is below. </p>
  
  <pre><code>javascript:window.location='tweetie:'+window.location
  </code></pre>
  
  <p>Clicking the above bookmark is the same as typing in "tweetie:<a href="http://google.com" rel="nofollow noreferrer">http://google.com</a>" into the address bar. This is obviously supported on the OS/Browser level, much the same as <code>tel:</code> URIs. Am I correct in understanding that developers can add arbitrary URI protocol specifiers as a part of app installation?</p>