SwiftKey Keyboard has been in beta ever since its introduction to the Android Market a few months ago. Having tried Swype, I also jumped on SwiftKey to give it a fair shot and ended up sticking with it. Yes, it was that good.
SwiftKey is different from other keyboards because it uses predictive recognition based on both tons of statistical information and your own typing habits. In fact, you can make whole sentences without typing a single key and just picking default suggestions.
Every company needs to make money at some point, and so today, having shed the beta status, SwiftKey is turning into a paid app.