Teaching note for CCJB-HBS-623092. Many markets are organized around platforms that connect consumers with complimentary applications and services. These platforms are two-sided because both sides - consumers and those providing applications or services - need access to the same platform to interact. A smartphone operating system such as iOS or Android, for example, serves as a platform that connects smartphone users with independent application developers who need access to the operating system's application programming interface to develop their apps. Other examples of platforms include video game consoles, e-commerce marketplaces, ride-sharing applications, credit cards, and social networking sites. This simulation gives students an opportunity to develop their skills in managing a platform firm. Working in teams, students acts as owners of one of two competing platforms. Taking into account such considerations as network effects, platform quality, and multi-homing, each team is responsible for designing their platform's strategies for pricing and R&D.