Wikipedia
iTap is a predictive text technology developed for mobile phones, developed by Motorola as a competitor to T9. It was designed as a replacement for the old letter mappings on phones to help with word entry. This makes some of the modern mobile phones features like text messaging and note-taking easier.
When entering three or more characters in a row, iTap guesses the rest of the word. For example, entering "prog" will suggest "program". If a different word is desired, such as "progress" or words formed with different letters but requiring the same keypresses like "prohibited" or "spoil", an arrow key can be pressed to highlight other words in a menu for selection, in order of descending commonality of their use.