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Dec 09

App Discover: An add-on that shows me when apps or user scripts are available for a site

Mozila, Tech, Web Browsing with tags: , Add comments

Greasemonkey and Fluid userscripts. AIR and the new Titanium apps. Browser add-ons. When you go to a website do you know if you are getting the best experience for you? You could search for script on userscripts, or Google for apps, but what if the developers of the sites had a way of pointing out that there were enhanced experiences for you?

This is where App Discover comes in. It is a Firefox add-on that notifies you of these very items. All the developer has to do is add a simple link tag to their page, and the add-on will find it for you.

For example, if Twitter added the following tag, you would be notified of TweetDeck:

<link rel="application" 
  title="TweetDeck Adobe AIR Twitter App" 
  href="" />

That line would mean you would see this in the browser:

Twitter App Discover Example

The type is a mime-type of course, and these are mapped into custom verbiage, but if you come up with something new… as long as the href is good, you should be golden.

I just added support for Appcelerator Titanium for example:

<link rel="application" 
  title="Tweetanium Appcelerator Titanium Twitter App" 
  href="" />

This is just a simple beginning of course. Where would we really want to go from here?

  • The current limitation is that it only really works well with one link tag (items get replaced)
  • I want to add preferences so the user can let the add-on know what they want to be alerted about (e.g. yes to Titanium apps and Greasemonkey scripts only!)
  • Be smart based on installation: E.g. if you don’t have Fluid (and especially if not on a Mac), don’t show it
  • Get social: “You have three friends who have installed TweetDeck”. This requires the browser being smarter about your social graph, which I think is a natural progression.
  • It should be smarter and not bug you when you go back to the same page. That can be fixed via the AnnotationService.

That leads me to XUL. I tweeted how it can feel a little strange to look up XUL docs and see dates in the lower 2000s. You have this nagging feeling of “has something really not changed since them? Is there an new better way of doing this?” As @mfinkle pointed out, “XUL is stable.”

I have to say thanks to the Ubiquity team who had done the lifting for me, which meant that this add-on took an hour to write!

10 Responses to “App Discover: An add-on that shows me when apps or user scripts are available for a site”

  1. Mark Finkle Says:

    The Prism add-on for Firefox does the same thing for Prism webapp bundles. Add a link rel=”webapp” and get notified in the same way.

  2. dion Says:


    Yah, perfect. I didn’t need to add anything specific for Prism as you already had it covered.



  3. sipper Says:

    So on what sites does this add-on work today? Is it useful for the general public *now*? Can you give examples of sites where it works?

  4. Aza Raskin Says:

    Now to hook it up to the social graph.

  5. Sean Burke Says:

    Is this able to see more than one application atm? Say if a project had a Air and Prism app and added the link how would the extension react at the moment? I am really interested in using this with future projects :)

  6. Sean Burke Says:

    I apologize (and feel stupid) I didn’t see the bottom of the post due to desktop clutter :x.

  7. dion Says:


    This is a proof of concept for how the browser could start doing this. Individual plugins already do this for themselves (e.g. Ubiquity can find commands, Prism can find webapps).

    I am most interested in getting people to collaborate and share the same link tag which would bootstrap this.



  8. dion Says:


    No problem. I need to make it support more, and allow you to change preferences so you can choose what you care about.



  9. Eric Caron Says:

    Has there been any luck getting this plugin submitted to be on I think this could get a lot of traction being in their system.

  10. Alan Jobs Says:

    What’s your browser? FF or Safari?

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