Imagine you are a growth hacker tasked with implementing strategies for a successful mobile app launch. Identify creative and cost-effective methods to increase app visibility and downloads, such as viral loop integrations, referral programs, and influencer collaborations. Outline a plan that includes user retention strategies and A/B testing to optimize conversion rates. The tone should be innovative and data-driven, suitable for a tech-savvy audience. Present your plan in a detailed report with actionable insights and expected outcomes.