It has potential but...

It does need work. The keyboard needs to have size options as well as have the choice to have the entire keyboard on one side when in Landscape mode. The fact that the Shift, Enter and Alt Char key is on the opposite side makes it inconvenient to type anything other than a basic text message.
Hopefully the developer is working on an update which will address these issues, otherwise Ill have wasted my money.

MissCristi about Handy - The One-Hand Keyboard for iPhone 6 and 6 Plus Quick & Easy 1 Handed Typing, v1.1