As a product manager, I would suggest developing a mobile app that offers personalized fitness and nutrition plans based on user goals and preferences. The app would use artificial intelligence and machine learning algorithms to create custom workout and meal plans for each user, taking into account factors such as age, gender, weight, and fitness level. In addition to personalized plans, the app would also offer a community feature where users can connect with each other for support and motivation. The community feature could include a chat function, forums for discussing fitness and nutrition topics, and the ability to share progress updates and success stories. To monetize the app, we could offer a premium subscription service that provides additional features such as access to certified personal trainers and nutritionists for personalized coaching and advice. We could also partner with fitness and wellness brands to offer exclusive discounts and promotions to our users. Overall, this app would provide a comprehensive solution for users looking to improve their health and wellness, and would have the potential to generate significant revenue through subscriptions and partnerships.