C# developers can write apps and watch ‘faces’ for this using .NET Micro Framework and Visual Studio 2012, it comes with its own Emulator to create and debug apps so you don’t need a watch to begin writing apps.
To get started this is all you need.
Download Visual Studio Express 2012
Download .NET Micro Framework SDK v4.3
Download AGENT SDK v0.1.1 (June 2013, Preview Release)
Scott Hanselman gave a sneek peek in a June post, @roguecode wrote a 3 part series to get started. There is also a post by @mikehole for communicating with Bluetooth devices then there is also a Tetris clone from Watch App and Watch Face Showcase and a Analog watch face from Ali Sufyan.
Agent comes with its own Big Digits Watch Face sample code
After installing the bits Visual Studio File > New > Project gets few more options
Click OK to create and debug a Watch Face application and built-in emulator fires up with a ‘Hello World’
If you have not written a .NET Micro Framework app before perhaps the API feels a bit low-level but fortunately there is a open source project that helps.
Hosted on github it gives you few helpers that I liked such as Button and Drawing, using this and Tiny Font Tool GUI I wrote a custom watch face that show a new message on clicking Middle Right button in emulator
So get started writing your own apps for your Agent SmartWatch.