Gamebook Companion is a mobile application designed for iPhone users, developed by Mark Stoneham. This app allows you to enjoy your favorite gamebooks, both classic and modern editions, on-the-go. You can manage your SKILL, STAMINA, LUCK, and equipment, engage in battles with monsters, and roll dice using its user-friendly interface.

The app features three main screens: the Character Sheet screen where you can set your stats and user-defined stats, the Equipment/Notes screen for storing items and notes, and the Combat screen where you can battle monsters by entering their SKILL and STAMINA values. You can also toggle the 'Auto-Battle' feature for automated combat resolution.