Successful developers have found that understanding what users do inside their app is the key to engaging and monetizing users in the long run. Various analytics tools are available that let you answer different types of questions. The easiest way to measure what users do in your app is to integrate a single analytics tool, such as Google Analytics, that's capable of answering all of your important questions.
With a unique Google Play Developer Console integration, Google Analytics can track how users move through the acquisition flow from marketing, to a Play store listing, to launching an app. The Behavior flow lets you easily identify roadblocks and successful features, so that you can improve user engagement. By implementing e-commerce tracking you can have a full view of the transactions, such as in-app purchases, happening in your app. And,