Picture of an eye 目 with emphasized eye-brows 首 to express the special: the head or the chief. (When used as a radical often without eye-brows 頁 meaning forehead). It is always at the right side of a character.
The app has many other functions, such as character selection according to difficulty, practice programs, handwriting recognition and success statistics!
on the pot 口), right: page, head 页 (=頁; head 目 with shoulders 八 and eyebrows 一)
