Appfour is perhaps the leading app developer for Android Wear. The team has published a variety of apps for the platform, including a web browser, a YouTube client, and a standalone email app. The team's newest project is a third-party keyboard for Android Wear 2.0.
If you've ever used Appfour's other apps, you should feel right at home. This is an upgraded version of the keyboard included with the team's older Android Wear apps (like the web browser and YouTube client). Instead of trying to shove all the keys on the screen (with mixed results) like the stock keyboard, this one spaces out the keys horizontally.
The stock Android Wear 2.0 keyboard (with English US layout).
Appfour's 'Keyboard for Android Wear.'
To use the keyboard, you have to swipe back and forth to find the key, and tap it. If that sounds tedious, it's because it is - but there's not really any good way to type on a watch-sized screen. Compared to the stock keyboard, this one has more special characters, swipe back to delete, and emoji. It works with every Android Wear app once you set it as the default input method, and doesn't replace the built-in voice typing functionality.
Personally, I think swipe typing on the stock keyboard is a bit easier to use than this. Appfour's keyboard is more exact, which made it perfect for entering URLs in the team's web browser. But I'm not sure if it makes sense for the usual quick responses that you would use a keyboard for on Android Wear. Still, if you want to try it out, you can download it from the Play Store below.