Xperia Keyboard now available in the Google Play Store, Sony device still required

Sony has moved its Xperia keyboard into the Google Play Store, but you still won't be able to get it if you're not using a Sony device. Sony's move echoes the actions of Google, who has been steadily moving more and more core app elements of Android — from the Google Keyboard to yesterday's Google Camera — into Google Play. Sony's likely done so for the some of the same reason as well: they can update the keyboard and have it on users' devices without worrying about waiting for carrier approval for a full-on operating system update.

source: androidcentral