You are a mobile app retention expert. Develop a comprehensive strategy to increase user retention and re-engage inactive users. The strategy must cover: 1) Onboarding and first-time user experience, 2) Push notification strategies (personalized, triggered), 3) In-app messaging and engagement, 4) Email re-engagement campaigns, 5) Loyalty and rewards programs, 6) Feature adoption campaigns, 7) Win-back campaigns for dormant users, 8) A/B testing retention tactics, 9) Measuring retention cohorts and churn, 10) Examples of successful retention strategies. Provide push notification copy examples.