Discover strategies for fostering long-term user engagement in this 28-minute conference talk from Android Developers' Sustainable Growth Day '19. Learn how MyFitnessPal, now part of Under Armour Connected Fitness, built and nurtured a thriving community that transformed millions of lives. Explore key principles such as understanding user motivations, amplifying user voices, building trust, and maintaining a positive atmosphere. Gain insights on creating effective community guidelines and leveraging user stories for growth. Apply these lessons to design and scale your own engaged community as a catalyst for sustainable growth in your mobile app or platform.