title: Check for updates to a JSON file online and compare it to a local stored file
body: <p>I'm out in the woods with this one: I have a universal, navigation-based app that displays data currently stored in a plist file. In a future release, I want to migrate the database to a JSON file on my server which the app can download to it's bundle, then parse it. Can anyone suggest a simple light-weight way of checking that the currently stored file in the bundle matches the version hosted on the server? Essentially checking for updates to the db without re-downloading the entire JSON file. </p>
  
  <p>Here's a snippet of what the beginning of the JSON file currently looks like. </p>
  
  <p><code>{
    "version" : "0.2",
    "description" : "1. Corrections to several entries.\n2. Added 21 new departments from Alameda &amp; Fresno Counties.",
    "counties" : {...............  *Rest of the JSON file here*    .....}</code></p>
  
  <p>My idea was to store the "version" ("0.2") value to NSUserDefaults and use that value to check against the available JSON file online every time the app launches.</p>
  
  <p>Am I on the right track or is there a better way of doing this altogether?</p>
  
  <p>Thank you</p>
  
  <p>Romeo</p>