This emerging technology report introduces the "WearableLearning" (WL) platform as a tool to exercise computational thinking and STEM learning for 5-12th grade students through mobile technology-augmented active game play and game creation. Freely available at "WearableLearning.org," it allows students and teachers to play, create, debug, and manage multiplayer, active games. To date, "WearableLearning" has been used in schools and afterschool programs by roughly 500 students and 25 teachers to create games covering STEM curricular content. "WearableLearning" enables the creation of physically active and social games, while offering possibilities for research on computational thinking, embodied cognition, collaborative learning, game-based learning, and practical applications of technology in STEM classrooms.