Free! TEACH YOUR MONSTER TO READ is a collection of four adaptive mini-games aimed at increasing how quickly and accurately students recognize letters (something that also goes by "grapheme" recognition for the purists among us). Young learners begin on Island 1, progressing through each mini-game to properly associate a series of letters and sounds ('s', 'a', 't', and 'p' in this case) until they've achieved mastery. The game play repeats itself across eight islands until the learner has mastered 31 different graphemes. It's a simple and straightforward process akin to leveling up through the Mushroom Kingdom in Super Mario Bros: game play remains constant as content changes depending on the progress of the learner. The entire game can be played over the course of a few days or weeks. Teach Your Monster to Read is provided free of charge with support from the Usborne Foundation (of Usborne Publishing) and works in your web browser on Mac or PC. Here's a handy PDF to get you started.
