CrossChat: Instant Messaging across Different Apps on Mobile Devices

Mobile instant messaging (IM) apps allow people from everywhere to chat with each other using mobile devices, but chat between different mobile IM apps remains a problem. For example, a user who only uses WhatsApp cannot chat with another user who only uses LINE. In this work, we present CrossChat, a system that enables instant messaging across multiple mobile IM apps. Specifically, CrossChat establishes a gateway on a mobile device to connect users running different IM apps and leverages user interface (UI) techniques to capture and exchange messages across multiple mobile IM apps at run time. A main advantage of CrossChat is that no modification to the original apps' software implementation is required to realize cross-app chat. We present several use cases to show the benefits of CrossChat. Experiments were conducted on mainstream IM apps, which show that CrossChat brings slight run-time overhead and can provide a smooth user experience.