Since little is known right now about KDK and the way it will integrate with Kindle software I can only speculate about which Kindle apps will be available. And this is precisely what I’m going to do.
Kindle Sudoku is likely to the among the first application to appear in fact I believe that there will be multiple versions of it by several companies. Sudoku is a very popular game, it doesn’t require fast screen refresh, colors and any computing power or memory. On top of that it’s not encumbered by trademarks or copyrights so everyone is free to implement it in any way they like. Kindle keyboard and 5-way controller are good enough for playing Sudoku (I have to admit that touchscreen with a stylus would have been the most perfect).
In fact if you look at Amazon’s official KDK page, one sample app that is displayed on Kindle there is Sudoku.