Introducing the Firefox OS App Manager

The Firefox OS App Manager is a new developer tool available in Firefox 26 that greatly improves the process of building and debugging Firefox OS apps, either in the Simulator or on a connected device. Based on the the Firefox OS Simulator add-on, it bridges the gap between existing Firefox Developer tools and the Firefox OS Simulator, allowing developers to fully debug and deploy their web apps to Firefox OS with ease.


Additional features made available in Firefox 26 are discussed in this post.

App Manager In Action

The App Manager replaces the current Simulator Dashboard and provides an integrated debug and deployment environment for your Firefox OS apps, by leveraging the existing Firefox Developer Tools. You can install hosted or packaged apps and debug them in the Simulator or with a connected device. The App Manager also provides additional information to the developer including the current Firefox OS version of a connected device, the ability to take screenshots, a list of all currently installed apps and a list of all the APIs and what privilege level is required to use each. Here is a screencast of the App Manager showing off some of the features available for Firefox OS Development.

In addition to debugging your own apps, the App Manager also provides the ability to update, start, stop and debug system level apps. Debugging an app using the Developer Tools is similar to debugging any other Web app and changes made in the Tools are automatically reflected real-time to the app either in the Simulator or the connected device. You can use the Console to see warnings and errors within the app, the Inspector to view and modify the currently loaded HTML and CSS, or debug your JavaScript using the Debugger.

Developer Tools

For more information about using the Developer Tools be sure to check out the Developer Tools series on this blog and for the most up to date information take a look at the Developer Tools section of MDN.

Getting Started with the App Manager

To get started using the App Manager take a look at the MDN Documentation on Using the The App Manager. Do keep in mind that to see what is shown above you need:

  • Firefox 26 or later
  • Firefox OS 1.2 or later
  • at least the 1.2 version of the Firefox OS Simulator
  • either the ADB SDK or the ADB Helper Add-on

Details for these are described in the above MDN link.

Mozilla is very interested in your feedback as that is the best way to make useful tools, so please be sure to reach out to us through Bugzilla or in the comments and let us know what you think about the new App Manager.

About Paul Rouget

Paul is a Firefox developer.

More articles by Paul Rouget…


  1. Peter Rukavina

    A great tool.

    One feature request, though: it would be nice if the “Update” button terminated the running app on the device if I was previously debugging it and restarted after refreshing to code.

    As it is, it seems like I need to manually terminate the app on the device itself, then update, then debug again.

    October 15th, 2013 at 10:01

    1. Paul Rouget

      Thanks for the feedback. It’s a known issue:

      October 15th, 2013 at 10:08

  2. Luigi Maselli

    Hi, i’m writing a FirefoxOs webapp but I’m having a weird behavior, on the FirefoxOs browser si OK, but if i save it on the homescreen..
    – the index.HTML seems to be cached at startup
    – the geolocalization request si ignored

    Do you know why?

    October 15th, 2013 at 12:02

    1. Robert Nyman [Editor]

      Is this on an actual device or in the Simulator?

      When it comes to caching, try and force-close the app or reload its contents (by a reload button in your app). To close an app, hold down the Home button and then use the Close button for the chosen app or flick the app display up. Also described in How to close an app on Firefox OS in our support web site.

      With geolocation, make sure that you have specified the correct permissions.

      October 16th, 2013 at 00:58

  3. Lorenzo

    Wow! That is awesome! Can’t wait to get started.. Great work!

    October 15th, 2013 at 12:07

    1. Robert Nyman [Editor]

      Thanks, glad you like it!

      October 16th, 2013 at 00:53

  4. Brett Zamir

    Very good screencast too.

    October 15th, 2013 at 14:53

    1. Robert Nyman [Editor]

      Thank you! We believe it’s extra helpful to have those when we have tools and workflows being shown.

      October 16th, 2013 at 00:53

  5. Rena

    So is there still a Firefox web browser or are we all expected to run an entire OS inside our existing OSes now?

    October 15th, 2013 at 16:09

    1. Robert Nyman [Editor]

      The Simulator itself is downloaded as an add-on. The App Manager dashboard and developer tools are in Firefox.

      October 16th, 2013 at 00:54

  6. Ken Saunders

    Worth mentioning here?

    App manager add-ons

    Bug 921500 – [app manager] landing page for the Simulator addon

    October 16th, 2013 at 09:26

  7. Myk Melez

    Recently I found a picture of the whiteboard where I originally brainstormed the outline of a “Webapp SDK,” which eventually became the Firefox OS Simulator. The outline’s list of features bears a striking resemblance to the ones in the App Manager, so I blogged about it!

    October 17th, 2013 at 09:28

    1. Robert Nyman [Editor]

      Cool, thanks for sharing that!

      October 18th, 2013 at 12:19

  8. Michael Greenwood

    Installed this Firefox addon!

    October 19th, 2013 at 16:46

  9. Wolf

    Tried it, it’s nice but I can’t seem to connect to my Peak device, followed all the steps on MDN. Not sure what to do next as I have a fairly standard setup (just Mac OS). I think it would be unhelpful to file a bug for that?

    October 21st, 2013 at 03:54

    1. Jason Weathersby

      Do you have adb installed on your mac? If so can you attach the peak and run the adb devices command from the terminal?

      October 21st, 2013 at 08:27

      1. Gabriele Vidali

        I’m trying with linux, aurora and adb helper from here and I’m curious if I can use adb to connect to the simulator

        October 22nd, 2013 at 13:09

  10. Jesus Israel Perales Martinez

    parece que firefox sera el IDE para desarrollar en firefoxOS , muy buena idea

    November 5th, 2013 at 10:33

    1. Robert Nyman [Editor]

      Yes, Firefox does become the IDE to use for developing for Firefox OS.

      November 5th, 2013 at 10:46

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