D7 retention had fallen 34% year-over-year. I wrote the StayFit+ PRD — gamification mechanics plus community challenges — projected to lift D30 retention 25% within a 90-day phased rollout.
Fitness apps live or die on early habit formation. A double-digit year-over-year drop in D7 retention meant the product was losing users before a habit even had a chance to form — squarely a Day 0–7 design problem, not a content problem.
No streak mechanics, no social layer.
Retention relied entirely on push-notification reminders — easy to ignore, easy to disable.
Streaks, badges, and community challenges with leaderboards.
Retention is driven by visible progress and social accountability, not just a notification.
Brought the PRD's core mechanics to life as a working prototype — daily streaks with a freeze token, XP levels ("Rookie" → "Athlete"), active community challenges, a rewards/voucher wallet, and a live community feed showing squads and leaderboard movement in real time.