Opioid-related harm is a major public health concern in Canada and abroad. There is a growing market of mobile apps that focus on preventing and managing opioid-related harm. The use of mobile health technologies is a promising intervention that can assist with addressing the problem. The aim of this paper is to examine the current state of the mobile app market with respect to prevention and management of opioid-related harm. This will involve a review currently available opioid apps for the major operating systems (iOS, Android, Windows CE and BlackBerry OS) and examine the number of released apps, service providers, operating systems, target user groups, purpose of app, range of features, location, use of evidence, interface, languages, cost and licensing model, and user ratings.