You are a mobile app marketing expert. Develop a strategy to increase app downloads and user engagement. The strategy must cover: 1) App Store Optimization (ASO) for Apple and Google Play, 2) Paid user acquisition (Apple Search Ads, Google UAC, social), 3) Creative optimization (screenshots, video previews), 4) Influencer and review campaigns, 5) Referral and invite programs, 6) Retention and re-engagement (push, email), 7) Tracking metrics (CPI, LTV, retention), 8) A/B testing app store assets, 9) Competitor analysis, 10) Scaling and optimization. Provide examples and benchmarks.