PhonoPix is a minimal pairs app with 10 decks for the following phonological processes: prevocalic voicing, word final devoicing, final consonant deletion, fronting (palatal and velar), marked blend reduction, unmarked blend reduction, gliding (“l” and “r” sounds), stopping, backing (palatal and velar), and initial consonant deletion. It has 400 pairs of words that contrast the child’s incorrect response with the target response. PhonoPix is a universal binary optimized for the iPhone, iPod touch, and iPad.