How to create an app extension for Sony SmartWatch 2

With a SmartWatch 2 extension, your users can utilise the features of your app without even picking their smartphone or tablet up from their bag or pocket. At the same time, you can get a lot of extra visibility for your app, since it will be exposed to all users of the SmartWatch 2. So are you ready to develop a new app extension or extend your existing app to support the Sony SmartWatch 2? We’ve put together a quick tutorial that shows you from start to finish, what programs you need, files you should use, and tools you can make use of, and the steps involved in creating your own app extension for Sony SmartWatch 2. Read more after the jump. (Updated 12 Nov, 2013)

If you’re new to creating app extensions for Sony SmartWatch 2, the following steps will walk you through everything you need to know to get you up and running with your app extension development.

How to get started in three steps

  1. Download and install the Android SDK. The Android™ SDK provides you with the API libraries and tools necessary to build, test, and debug apps for Android.
  2. Download and install the latest version of the Sony Add-on SDK from the Sony Add-on SDK installation page. The Sony Add-on SDK is an add-on to the Android SDK that includes the Smart Extension APIs.Those are easy to use, intent-based APIs that make it possible to access the display, notification, and other general controls on SmartWatch 2. The Sony Add-on SDK comes with full code examples for Smart Extension APIs, an emulator, and API references.
  3. In the Sony Add-on SDK package, go to the samples > SmartExtensions folder, and select the Smart Extension API sample application that is most relevant to your app extension.
Sample Smart Extension APIs included with the Sony Add-on SDK package.

Sample Smart Extension APIs included with the Sony Add-on SDK package.

How to create your Smart Extension in Eclipse
Create the Smart Extension API sample application using Eclipse. For example, here’s how to create a Notification API sample application using the SampleNotificationExtension:

  1. Start Eclipse and navigate to: File > New > Other.
  2. Expand the Android directory, then select Android Sample Project.
  3. In the Select Build Target option, select Sony Add-On SDK 2.0.
  4. Click Next to create the sample application. In the Select Sample dialog box, select an appropriate sample based on the purpose of your application, for example, “SampleNotificationExtension”. Also enter the appropriate sample names here, making sure to name the sample accordingly, so that you know what the sample is for.
  5. Click Finish. Your project should now be created in the Package Explorer of the Eclipse. Note: The first two sample codes that should be imported are SmartExtensionAPI and SmartExtensionUtils. All other Smart Extension sample codes will need these library projects.

In addition, you also have the API references available online to provide you with the details and capabilities of the Smart Extension APIs.

How to run the application on SmartWatch 2
To run the sample application on SmartWatch, follow the steps below:

  1. Make sure the Android smartphone or tablet is connected and paired with SmartWatch 2.
  2. Connect the Android smartphone or tablet with the machine using USB.
  3. Make sure Android Debug Bridge (adb) is running and the device can be detected. You can download adb from the Android SDK main page.
  4. You can now directly run the Smart Extension code example in Eclipse on a selected device using Run > Run As and then selecting the device.
  5. The Smart Extension code example will install on the device and should also be visible on the accessory.

How to use the Accessory Emulator
To run the Accessory Emulator on an Android smartphone or tablet, follow the steps below:

  1. Download Smart Connect from Google Play™ and get the accessory_emulator.apk from the Sony Add-on SDK package, then install them on the smartphone using adb. Note: Smart Connect is already installed if you are using a Sony Xperia™ smartphone or tablet.
  2. Connect the Android smartphone or tablet with the machine using USB.
  3. You can now directly run the Smart Extension code example in Eclipse on a selected device using Run > Run As and then select the device.
  4. The Smart Extension code example will install on the device, and should also be visible on the Accessory Emulator application.
  5. Open the Accessory Emulator app from the app tray. For more information on the emulator, refer to the Accessory Emulator section in the How to use the Smart Extension APIs document.

Distribute your app and get valuable exposure
Create an APK file to publish on Google Play™. To make your app show up in the pre-defined Google Play™ search, just make sure the Google Play™ description for your app includes the following string (we recommend at the bottom, on its own line):

Smart Connect extension for SmartWatch 2


We hope you find this guide helpful for creating apps for SmartWatch 2. If you have any questions, feel free to drop us a line in the comments field below, and we’ll be happy to get back to you with an answer as soon as we can.

More information

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  1. By Sandeep Kirankirk


    i just found unofficial app from external sources. now the problem is how do i install this app on to my watch. when i install it installs into phone but not on watch. please help.!!

  2. By Subhranita -


    I want an app by which I can view images stored in my tab on my Sony smartwatch 2 with zoom option, ability to change the image by swiping it and easy scrolling.

  3. By Daniele Farris


    If I understood well, there is no way to talk directly to the smartwatch.
    The app runs on the smartphone that, in turn, makes calls to the smartwatch.
    If so, can you please tell me the reasons of this architectural choice?
    If there is a way to actually talk to the smartwatch directly (e.g. via bluetooth), how can I develop such solution?

    • By Marlin Sony


      Hi Daniele:

      We have received some similar requests for access to the Bluetooth stack directly, however development has ended for SmartWatch 2 so no future updates will be made. We will keep this in mind for future products however.


    • By Marlin Sony


      Hi Daniele:

      Can you clarify what you mean by “talk to the smartwatch directly”? Do you mean sending raw bluetooth commands? What are you trying to accomplish exactly?

      Marlin from Developer World

      • By Daniele Farris


        Sorry I was not clear at all. Thanks for replying.
        I am not an expert first of all so sorry for possible conceptually wrong questions.
        I would like to utilize the smartwatch bluetooth protocol as I/O for the smartwatch itself. Example: play a song via another device sending some commands via bluetooth. Instead of using the touchscreen as I/O, simply utilize the bluetooth.
        The smartwatch then communicates with the phone with its own library, regardless that I selected that song via the touchscreen or via some other I/O (i.e bluetooth)…There should be then a way to deploy some drivers in the smartwatch itself (without passing via the smartphone) and that is my question.
        I have read something about the Pebble smartstrap, where you can I/O directly to the smartwatch thanks to some contacts in the watch strap (e.g. with some sensors).
        I hope my question is clearer, thanks for reading!

        • By Marlin Sony


          Hi Daniele:

          Ok, so if I understand correctly you are asking if it is possible to connect the SW2 to another bluetooth device directly without the use of a phone? That use case is unfortunately not possible.

          The SW2 API does not allow access to the low level BT stack and connecting to an external device would have to go from the SW2 to the phone to the external device.

          Hope that answers your question!

          Marlin from Developer World

          • By Daniele Farris


            Yes Marlin it answers my question, thanks a lot.
            I am curious to know why such APIs are not available (as specified in my first question). It would be nice for many application (e.g. connecting two smartwatches).


  4. By Roy Yokoyama


    Sony Smartwatch 2 is great. I recommend another feature for the watchface.
    Pebble can switch the watchface easily by pressing or buttons on the side of watch.
    It will be great if the SmartWatch 2 can switch the watchface by pressing the button and bring up a menu to switch the installed watchfaces. (Currently, we need to go to Settings->Watch faces to select the desired watchface.) Basically, the pressing the menu button in the watchface screen bring up the Watch faces selection)

    • By Joe Padre


      Hi Roy,
      Thanks for your feedback. We’ll pass on your suggestion to the SmartWatch 2 development team.
      Best regards,
      Joe from Developer World

  5. By kunal mehta


    Hi. I wanted to show a custom layout when the watch is locked simile like watch faces application. can you give me some guidance on that from where to start.

  6. By Kolja Kieslich


    Can you please update this post? Even after an OS reinstall i’m getting the same errors. After importing SamplePreferenceActivity i get alot of: Control cannot be resolved to a variable, R cannot be resolved to a variable, mContext cannot be resolved to a variable, Extension cannot be resolved to a variable, etc.

  7. By Marius Vosylius


    Is it possible to create new activity that would trigger on onMenuItemSelected?

    • By Marlin L


      Yes, you can start an Activity the same way you would from any standard Android app.

  8. By Sagar Devanga


    I am getting an error when i try to run the sample control extensions

    [2014-02-14 12:56:11 – SampleControlExtension] Please check logcat output for more details.

    what could be the solution

    • By Joe Padre


      Hi Sagar,
      Usually that error means that one already has an older version installed that is incompatible. Try uninstalling the old version and then install the new version and it should work.
      Best regards,
      Joe from Developer World

  9. By PJ Olson


    How do I remove this application from my SmartWatch?

    • By Joe Padre


      Hi PJ,
      To remove an app from your SmartWatch, just uninstall the app from your device, and it will be removed from your SmartWatch as well.
      Best regards,
      Joe from Developer World

      • By Marius Vosylius


        Hi Joe, Im not unable to remove Sample Notification app. There’s no option to do it.

        • By Joe Padre


          Hi Marius,
          From your device, try Settings -> Apps -> Downloaded -> SampleNotification -> Press uninstall.
          Best regards
          Joe from Developer World

          • By Marius Vosylius


            Thanks Joe, it did work fine. But another issue I have: Installation error: INSTALL_FAILED_UPDATE_INCOMPATIBLE. This erros comes in then I have SampleApp, but my phone is clean.

          • By Joe Padre


            Hi Marius,
            try uninstalling, restarting the phone, and then installing.
            Best regards,
            Joe from Developer World

  10. By Jarl Wijman


    what be really be great is if Sony would respond to customer concerns, on their forum and community site.
    i see hardly any responses from Sony, this really worries me

    concerning the Smartwatch 2, it really needs more watch faces, or a way we can create our own, and a selectable screen timeout

    • By Joe Padre


      Hi Jarl,
      Thanks for taking the time to share your feedback on SmartWatch 2. We will forward your suggestions to the HW/SW teams responsible for SmartWatch 2 development.
      Joe from Developer World

      • By Leo Wandersleb


        So the question and reply regarding watchfaces imply there is no way we can create watchfaces? I’m slightly shocked and I’m interested to hear what the hw/sw guys have to say, too.

        • By Joe Padre


          Hi Leo,
          The functionality to create watch faces is not available at the moment, but the teams working on the product are looking into this.
          Best regards,
          Joe from Developer World

  11. By Cyma Real


    i am stuck in the step:- “How to create your Smart Extension in Eclipse” step 4

    in the select Sample dialog box, i do not see “Add Link to API overview – Notification”.
    which one should i pick up?

    Since then, i get lost, i do not know what to do about the imported “SmartExtensionAPI” and “SmartExtensionUtils”.

    • By Joe Padre


      Hi Cyma,
      For that step, the example should be: ‘SampleNotificationExtension’.
      Hope that helps. Please let us know if you need any other help with creating your extension.
      Best regards,
      Joe from Developer World

  12. By Edward De Jong


    I am familiar with the ipod Nano, which had a few hard-coded apps. Is the smartwatch 2 capable of launching an app from the watch itself? or does the mothership phone have to be powered on, and nearby, in order to run? Does this device only run in a tethered mode therefore? Can one load an app from a PC or Mac into the phone directly, like you can into an iPod touch with a USB cable or wifi, or does this device only connect to an android phone? Seems like Sony needs to be a lot clearer about how this device gets and runs software. I have made over 70 iphone/android apps and am very interested in the watch market, but for the ecosystem to really take off you have to have an easy way of getting software. The samsung watch seems DOA to me, it requires specific samsung devices to load the watch, which is a disastrous mistake.

  13. By Jarl Wijman


    can i also use this sdk to create new watch faces for the Smartwatch 2?

  14. By Andy Aspell-Clark


    So, I’ve finally worked this out.

    Once you have created the “SmartExtensionAPI” sample project:
    1. open it’s properties and mark it as a library.

    Now create the “SmartExtensionUtils” sample and open it’s properties.
    1. mark it as a library
    2. add the SmartExtensionAPI as a library for the Utils project.

    now it compiles 🙂

    • By Joe Padre


      Hello Andy,
      Glad to hear it compiles now. 🙂 Let us know if anything else comes up. By the way, which one of your apps are you planning to extend to SmartWatch 2?
      Joe from Developer World

      • By Andy Aspell-Clark


        The first projects I am going to extend are my training plan viewer and contact lens tracker.

        I’m also going to see if I can find some uses at work with my apps.

  15. By Andy Aspell-Clark


    Even re-doing all the steps after uninstalling SDK 1.0, and re-creating the sample projects I still get the same error.