Wi-tri is a personal, triangular smartphone that can do anything for the user. Shake and Frylock owned one for a short period of time. Their name is a pun on "Wi-fi". Aside from being essentially limitless in what tasks it can perform (being seen gardening, mowing the lawn, and creating giant watermelons), it is also a camera, web browser, entertainment system, home theater, financial adviser and future planner.
In reality, the Wi-tri are a sentient race of triangular beings posing as smartphones. They are capable of mating with each other, and their purpose is to 'tri-form' the Earth by turning everything into triangles. One Wi-Tri stated that the Aqua Teens could stop them, but they simply did not have the discipline, which is correct, as Meatwad tried several times to convince Frylock to "shoot them with [his] eye lasers." Another Wi-Tri told Frylock that the plan wouldn't be done until long after the Aqua Teens are dead and that, because none of them have children, they have nothing to worry about.