When I've purchased paid apps for my phone or tablet, in the pay I've always bought them through Spamazon, mainly because when I flashed a new ROM, they'd be available to reinstall without any fuss. Last Saturday, I noticed that the Swype keyboard was out of beta, and available at the Google Play store for only 99 cents. I had been using the public beta on both my phone and my tablet (yes it can pre-installed on my EVO 3D, but there were more features on the beta), abd I was sufficiently impressed with it to buy it. But it was only available on Google Play for now. So I figured what the hell, I put my credit card in (ordering it from my computer) abd it was pushed to both my devices.
And I'm impressed. Especially on the tablet (it will work on both the phone and the tablet). It is now my default keyboard. I highly recommend that you buy it....