The extent to which applications on a particular platform are also available for buyers of competing platforms is called platform-level multihoming. In this research paper we explain one of the motivations for mobile platforms, such as Apple and Google, to implement multihoming, namely it is the existence of a positive cross-platform spillover effect. To study the spillover effect between platforms we examine a ranking effect as a primary effect: if a game enters into a top 100 chart on one platform, the sales of this game on another platform will increase. Our results suggest that the spillover effect is asymmetric: Apple has a stronger spillover effect on Google than vice versa. To empirically test our hypotheses, we utilize game-related data from Apple's App Store and Google Play and implement dynamic panel data models.