Technological advancements in electronics have provided access to quantitative methods of measuring balance or postural stability. In the past decade mobile devices have added built-in motion sensors called tri-axial accelerometers. Developers are accessing the accelerometer outputs while the device is against the body, and translating the values to postural sway and/or stability. PURPOSE: The purpose of this study was to assess balance in high school athletes using a mobile device software application using accelerometric motion sensors in order to provide information for concussion management and return-to-play. METHODS: 121 healthy high school-aged athletes (62 male, 59 female; average age = 16.1 plus/minus 1.3 yr) performed a series of balance tasks (bilateral, tandem, single leg) over multiple visits. Age, sex, orthopedic injuries post concussions, height, and weight were also recorded. RESULTS: Balance scores for concussed athletes did not show any significant difference between baseline and post-concussion test; however, there were three large effect size and one moderate effect size calculated. No significant differences were observed in balance scores between ages. CONCLUSION: Balance or postural sway is one of many important factors in providing vital information to help medical professionals determine proper management and return-to-play. Mobile devices with tri axis accelerometers is a new innovative and cost-effective method to measure human balance, however, more research needs to be completed to assess its effectiveness in identifying potential impairments resulting from sports concussions or mild traumatic brain injury.