The world is facing a major challenge on population aging and falls present a substantial health problem among the older population. The study is aimed to develop a reaction test App for assessing cognitive function related fall risks in older people. The developed App was tested on one hundred Korean women, consisting of twenty young healthy adults (age: 22.5 +/- 0.6), forty community-dwelling older people with no history of falls (nonfallers; age: 72.5 +/- 4.4) and forty matched older people with a history of falls (fallers; age: 71.8 +/- 4.8). Simple reaction time and information processing speed of participants while performing the reaction test with the developed App were derived through a log-linear regression between the reaction time and number of equi-probable alternative choices based on Hick's law. Older people showed significantly longer simple reaction time and slower information processing speed than the young group. Even though there was no significant difference between older nonfallers and fallers on the simple reaction time (p = 0.54), the older fallers had significantly slower information processing speeds than older nonfallers (p < 0.001). Further, receiver operating characteristic analysis revealed excellent discriminative ability of information processing speed on classifying fallers and nonfallers, with sensitivity of 85% and specificity of 70%. These findings suggest slow information processing speed from the reaction test is an important risk factor for falling in older people. The developed reaction test App can be a convenient assessment tool for the older individuals and healthcare professionals to test cognitive function related falls risks. (C) 2017 Elsevier B.V. All rights reserved.