If you love your new iPhone 6/Plus but find yourself missing the convenience of one-handed typing, One Handed Keyboard may be the third-party keyboard for you. It’s a system-wide keyboard exactly the same size as the one on the older and smaller iPhones so everything will feel familiar. The “sliding over” keyboard method is what Samsung and LG have been using on their Phablets for years.
The keyboard can be switched between left- and right-handed use, and when you want to return to two-handed typing, just hold down the spacebar to expand it to full width …
The keyboard automatically switches between dark and light themes, depending on the app in which it is used, or you can manually choose your keyboard color.
One Handed Keyboard costs $1.99 on the App Store. The one drawback is that you lose the excellent iOS 8 predictive text and get a more basic auto-correct instead. But if thumb-typing is your thing, that may be a price worth paying.