Multi Player Option and Monetisation of App

I am looking to build a game app for the Android platform. My goal is to create a multi-player option within the app, as well as monetize it using in-app purchases. The features of the app will include engaging gameplay, a seamless multi-player function and a reliable system for users to purchase and sell virtual items. The app will be easy to use, secure and provide an enjoyable user experience with vivid graphics and an intuitive interface.