[This post is by Ambarish Kenghe, who’s a Product Manager for Google TV — Tim Bray]

While the add-on does not contain all features of Google TV, it enables developers to emulate Google TV and build apps using standard Android SDK tools. It also provides new APIs for TV interaction, such as TV channel line-up. Google TV emulation is currently supported on Linux with KVM only, and we are working on support for other operating systems. We’re very happy that through KVM we’ve been able to create a fast Android emulator for TV.

Depending on the design and use case, an existing Android app may work well on Google TV as is, or it may require fixes. With the add-on you can test your apps to determine if they would be a good fit for TV and whether any tweaks are required. We are also publishing UI guidelines to help you with topics like optimizing for D-pad navigation, presenting information for 10-foot viewing, designing apps that work well across devices, etc. The guidelines include information on how certain UI elements on Google TV differ from other Android devices.

As with other devices, apps that require features not supported on Google TV won’t appear in Android Market on Google TV. For example, Google TV-based devices do not have a touchscreen; hence apps which require touchscreen will not appear. Conversely, if the manifest says touchscreen is not required, the app will appear. Please follow our guidelines carefully.

These are still early days for Google TV, and this release is another step in providing developer tools for the big screen. While the number of apps available on TV will initially be small, we expect that through this early release of the add-on you'll be able to bring optimized TV apps into the ecosystem more quickly. To start doing this, download the Google TV add-on today. Also, please continue to reach out to us on the Google TV Android Developer Community forum. We look forward to your contributions!

Source : Android-Developers