We report an experiment conducted to assess the usability of a smartphone-based controller for use by dismounted troops using unmanned ground vehicles for reconnaissance and surveillance. A virtual joystick controller is compared to a specially designed tilt-based controller intended to limit the device’s touch interface while providing intuitive control. Participants drove a small tracked robot on an indoor course using both controller options where metrics regarding performance, mental workload, and user satisfaction represented various measures of controller usability. Results indicate that the tilt controller is preferred by users and performs equally as well, if not better, on most performance metrics. These results support the development of a smartphone-based control option for military robotics, with a focus on gestural input methods which overcome deficiencies of current touch-based systems, namely lack of physical feedback, high attention demands, and unreliability in field environments.