Coco is an app implemented as a Praat script which enables speech therapy students to practice the pronunciation of Flemish vowels in monosyllabic words. The student pronounces a word, and the program shows the position of the vowel in the vowel triangle and in relation to the position of the vowel as pronounced by the standard speakers. The student must try to hit the vowel position according to the pronunciation of the standard speakers. The program gives instructions that tell the student how to come closer to the target point.