This document summarizes how to effectively test A/B applications using Firebase. It presents examples and case studies from real games. Tools used include the Unity 3D game engine for client development and Firebase for the server. The document discusses what types of game aspects can be tested, such as gameplay, UX, business models, and provides two case studies comparing setups focused on retention/networks versus monetization. It demonstrates how Firebase can be used to configure different experiment variations and provides examples of ad placement, mechanics, and interface tests.