This concept is to serve as text input method – with a single tap on a single button, while the button changes states of the character to be input, it is meant to be a part of a spelling game.
In the game, the entire alphabet cycles within that button, each getting displayed for a set amount of time but the ones in the string get displayed for a longer duration so that the user can tap on it. So, if the word to be spelled is PROGRESS, the letters displayed the longest in the button would be E, G, O, P, R and S.
As a keyboard, (which would definitely not be a great use for this), the cycle would start in the usual manner, but would allot the greatest time-duration to the letters which are the most used as first letters – as the taps occur, this would eventually do a lookup of dictionaries for that first letter and allot time weights to appropriate letters based on their positions and frequency. If not as a keyboard, this could be the easy or training mode for the tapping game.