Audience retention for mobile apps can have a strong impact on ROI. App developers spend a considerable amount of time and resources trying to acquire new users that have never used their apps before, but re-engaging existing users can be a cost-effective, savvy way to get your existing audience excited about using your app again. As an app developer, you know that retention and engagement rates matter and that the number of downloads is not the only important KPI when determining ROI. In fact, MobyAffiliates claims that 1 out of every 4 apps that are downloaded to a device are…