A group-challenge app and a website where every figure is sourced

A catalogue of templates (exercise, health, screens, money, home) or a custom challenge: a number, a unit and a rhythm, per day, per week or every X days. “Don’t exceed” challenges (screen time, sugar, alcohol) go from green to amber to red, and a deadline freezes the final ranking.

“Done”, +1, a set of push-ups, a timer or a number: each kind of challenge has its button. A forgotten day can be caught up from the calendar, and one entry counts in every challenge it belongs to.

Each participant’s bar, the time left before midnight, a calendar with one bar per person and an activity feed. Emoji reactions arrive as notifications, and an evening reminder only goes out if something is left to do.

Optional and private by default. Scan a product’s barcode with the camera, or search for a food: the data comes from the French Ciqual table (Anses) and Open Food Facts. The calorie goal is calculated with macros, and within a challenge you choose what others can see.

A weight curve with BMI and a private waist measurement, a wellbeing check every two weeks based on the WHO-5 questionnaire, fasting challenges and daily routines, alone or with others. Every health figure stays private and can be deleted.

Trophies, duels, levels and ranks, a forfeit or reward chosen by the group. No followers or public profiles: you invite with a link or a code, a supporter (coach, physio, relative) can follow without being ranked, and a parent manages their children’s counters.

A first name is enough to start, with no email or password. Web, iPhone and Android share the same code and a real-time back end, and the rules are enforced by the server: the day is calculated in each person’s time zone, and the phone’s clock cannot be used to cheat.

The challengeus.app website publishes articles on habits, nutrition and motivation. Every reference is reopened at the source with a verdict (solid, nuanced, weak, myth), and a human reviews before publication.