HERO Keyboard by Corey Stone is a keyboard app that arranges the letters based on the frequency of use in the English language to make it easier for the user to type with both their thumbs. The keyboard consists of three concentric rings surrounding a circular "space" button. More frequently used letters displayed larger and more centrally than less frequently used letters. As a result of this configuration, the letters at the top of the first ring spell out "HERO", hence the name of the keyboard.
