New version adds Korean support
As part of Google's ongoing effort to spin off certain software features into Google Play for easier updating, the company has today launched the Google Text-to-Speech engine as a standalone app on the Play Store. The will push out automatically to those using an older version (not you, Nexus 5 owners, you're already up-to-date out of the box). If you install it on a device that doesn't have it already, it'll appear as an option alongside whichever manufacturer-loaded text-to-speech service is currently in use.
The only major change we're seeing compared to the older pre-loaded version is the addition of Korean as a supported language. However the ability to update text-to-speech without requiring an OS upgrade presents the possibility of Google introducing more advanced TTS features through future app updates.