Time for a little history lesson. Way back in the summer of 2010, when smartphone screen sizes were still reasonable and people were still complaining about how hard it was to type on them, a little company called Swype Inc. thought it had the problem of touchscreen input licked. Android users went crazy trying to get into the beta for their gesture-based software keyboard, and tech blogs threw around words like "innovation" and "miracle" like rice at a wedding. Then the other shoe dropped: Swype was only interested in selling its slidey wares to hardware manufactures, as a tie-in for brand new phones - they had no intention of selling their nifty keyboard directly to end users.
Fast forward three years. Swype has been acquired by the dictation specialists at Nuance, makers of the Dragon Naturally Speaking software. Since their new owners are interested in the novel concept of making money, they've finally decided to unbind the Swype keyboard from hardware partners and sell it directly to consumers on the Play Store. It's right there if you don't believe us - you can buy it right now, for just a dollar.
Of course, three years might as well be twenty when it comes to the mobile market, and in that time plenty of competitors have risen to meet and in many cases beat Swype at its own game. Keyboards like SlideIt and SwiftKey were more than happy to serve the users that Swype wouldn't, to say nothing of the built-in gesture typing in Android Jelly Bean 4.2. All that said, it's not as if the Swype team have been sitting on their hands. They've added two-handed swipe typing, some impressive word prediction, and integrated the Dragon Dictation speech-to-text engine.
Update: At the time of writing, the keyboard is only available for smartphones. The app description specifically mentions robust tablet support, so there's probably some compatibility wires crossed somewhere.
There's also a free trial version for anyone who wants to give the keyboard a spin, though it's also limited to phones for some reason. The trial app is the second Play Store widget below.
Update The Second: It looks like they've sorted out tablet compatibility.