Back in January, Amazon invited outside software developers to create applications for its Kindle electronic reader — heralding the start of a Kindle app store. Since that initial announcement, however, it's been pretty quiet, with Amazon releasing just two free word games for Kindle. Now Amazon is introducing a third Kindle app — of the popular board game Scrabble. This one is paid, costing $4.99.

With just three games, it's not exactly a thriving app store yet. Amazon originally announced the Kindle app program shortly before Apple unveiled the iPad — presumably to steal a little thunder from the iPad hype and show that Amazon can tap the Apple App Store model as well. It will be interesting to see if Amazon follows through and allows a Kindle app ecosystem to take root.

Given the current design limitations of the Kindle — its lack of color, touch screen or animation — Kindle apps will presumably be of the fairly basic, black-and-white variety, at least for now. Scrabble, as you can see from the images below, fits that mold. Amazon Vice President for Kindle Ian Freed has talked about the potential for things like calculator and stock ticker apps for Kindle and next-generation e-books with search features, interactive quizzes or audio.

The Scrabble app for Kindle was developed by Electronic Arts. According to Amazon, Electronic Arts set the $4.99 price tag for the app. (Amazon, by the way, calls its apps "active content.")

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