ChatHeads
ChatHeads is a suite of iOS jailbreak extensions which implements Facebook-style floating message heads across iOS, for a multitude of messaging apps, including the stock Messages app, Facebook Messenger, and WhatsApp. When a new message is received, the client app extension performs an interprocess communication (IPC) call to the ChatHeads host extension (running on the SpringBoard), transmitting conversation information, including sender name & photo, message body, client extension app, and conversation Id. The host extension then animates a new chat head from the source of the message. The user can tap the chat head to open a hosting view containing client app, opening to the conversation so they can view the message in context, and reply.
By far, the most complicated runtime extension / jailbreak tweak I've developed, ChatHeads features a fully custom, high-performance, low-latency messaging UI, with smooth animations, and app-agnostic data schema. It was designed to be a universal, extensible solution for all messaging apps, allowing for a consistent user experience across a variety of different app appearances, centralizing all messaging functionality into a global context, and providing a consistent user experience across a variety of different apps.