Mobile computing devices (smart phones, tablets, etc.) are rapidly becoming the dominant means of communication worldwide and are increasingly being used for scientific investigation. This technology can further our Extension mission by increasing our power for data collection, information dissemination, and informed decision-making. Mobile computing applications (apps) with relevance for Extension can be divided loosely into three categories--information delivery, collaborative research/participatory sensing, and self-assessment. Examples can be found in all Extension fields of inquiry, from agricultural production, pest management, natural resources management to youth science literacy and managing nutrition and fitness.