HM Semi de Paris is an official application by Harmonie Mutuelle Semi de Paris catering to both participants and spectators of the event. For participants, the app offers tailored running preparation guides and training plans, exclusive gifts through challenges, detailed training tracking, and the ability to compare progress with friends and family also participating in the event.

To use the app, participants need to download it, connect with their time to account, link their running app or smartwatch, train, and track their progress. Spectators can follow up to 10 runners live, check the participant list, track runners' real-time locations on the map, view category rankings, and share participant progress on Twitter automatically at each kilometer.