I know Smart Watches are a really new technology and Im looking to develop for all Smart Watches. I've been looking around and cant find much on developing for Smart Watches and I was wondering if the Sony's SDK is compatible with other Smart watches using Android as an operating system?
As far, there is no unified SDK to use with all Smart Watches. In my opinion there won't be very soon, as the Smart Watches from different companies are build on different platforms and have very different features.
The Sony Add-on SDK can be used for all devices that support Smart Extension APIs, which are:
SmartWatch 2, SmartWatch, Smart Wireless Headset pro, Stereo Bluetooth Headset SBH50, Smart Bluetooth Handset SBH52.
For more information, see: http://developer.sonymobile.com/knowledge-base/sony-add-on-sdk/about-the-sony-add-on-sdk/
Update: You can manage smart accessories from any smartphone which have installed the Smart Connect application. So you can use the SDK also with non-Sony devices, but you can control just the Sony accessories I mentioned.
Smart Connect for non-Sony devices is available in Play store: https://play.google.com/store/apps/details?id=com.sonyericsson.extras.liveware