SwiftKey is a 3rd party keyboard app that is able to predict your next word with incredible accuracy, based on what you've already entered. SwiftKey enables a person to write up to 50% faster by predicting up to 1/3 of next words instantly. SwiftKey learns and adapts itself to suit you.
SwiftKey Keyboard has recently implemented a feature that other keyboards don't offer: speech to text. Dealing with the way consumers are with text inputs; this is a feature that will make or break a keyboards use. Text-to-speech will most likely become a standard among other keyboards. The feature gets a dedicated button to the left of the space bar, but the implementation is slightly different from what most of us are used to. Pressing it brings up a blank screen with the "Speak Now" dialog rather than staying on the screen you're actually entering text on. While slightly jarring, this may be due to one other tweak--after speaking, a pop-up lets you select what you meant to say. Download link and another screenshot after the break.