I guess it all comes down to whether they come with a web browser. Tinzen (Linux) and Google (Android) might support Chrome or Firefox, which supports HTML5. Apple (iOS) will ship with a browser, most likely Safari, which doesn't support HTML5 completely. Apple wearables might support Firefox. These wearables seem to be only extensions of another device, similar to Bluetooth headsets, which need to be paired to another device in order to work, or mere blood pressure devices (Google Fit).