Zwei

My initial driver to develop an iPad keyboard was to allow users to not have to look at the keys in search for the next letter. Thus, the eight button design was born. One button for each pinky, pointer, ring and middle finger. With that design, the user is supposed to place each finger above the buttons once and then just tap with the one/ones corresponding to the current letter. While it works fine, holding the hands still or getting them into the correct position to be able to hit the buttons can be challenging. So I kept looking for a better way to achieve my goal. During a WWDC presentation, a blind Apple engineer demonstrated some accessibility features and while I watched him orient his fingers on the iPad he was using I realised that this needed to be my goal: The keyboard should be designed with blind people in mind.
So with ‘Zwei’, I reduced the number of buttons to two (Zwei is the German word for 2), each spanning half of the screen’s width. Based on the number of fingers used to press one of these buttons, the user is presented with 5 characters. The first gets entered by simply releasing the button. Each of the remaining can be selected through a swipe gesture (up, down, left or right). In addition, while pressing the first button, the second button offers two functions that can be activated by tapping it with either one or two fingers. Examples for these functions are changing the input mode to upper chase letters, to delete the last character or the obligatory switching to the next keyboard.
Again, I think the app preview video will explain it much better

When the accessibility feature “Voice Over” is activated, the two buttons increase their height to half the screen as well. Characters are read out once selected and a confirmation sound is played when the character is chosen. I implemented this in contrast to the standard settings which announces the letter twice: once the button is touched and once the current button is released.