피온북 is a free Android application designed to enhance the online football game FCO by providing essential information and features. Users can access the latest updates on all players, allowing them to search for various player attributes and check the historical performance of team owners, including their match and transaction records. Additionally, it offers up-to-date information on team colors and manager details, facilitating better squad formation strategies.

The application also includes a squad simulation feature, enabling users to create virtual teams by selecting desired players while adhering to salary cap limits. Users can evaluate players on a scale of up to five points and engage in discussions via forums and reviews. Furthermore, it provides a real-time chat function that activates during actual football match times, allowing users to share information and engage in discussions with fellow players.