LG G2 keyboard is well-known by its themes and customization, check out some for more info:
Like them? You can now get them without root access thanks to XDA member gerardroid with all its features!
The whole app can be downloaded HERE and can also be installed in usual way.
However, if your device is rooted, you can get some extra features - 5th row, split keyboard, emoji and more.
These functions can be enabled in build.prop navigated in /system using root browser. To enable these features, download the app (version for rooted devices) and simply add these lines after the text (do not delete the previous text in build.prop):
Then save the build.prop and finally reboot your device to take the effect.
Do not try to modify your build.prop file without having a nandroid backup - if a problem appears, you may be stuck in bootloop and brick your device without a return!