IAC on iOS
GCDWebServer is an embeddable and lightweight http server for Mac and iOS. On iOS it runs as a background task — it keeps running even when your app isn’t in the foreground.
Picture this: app X wants to send some data to app Y.
App Y is running GCDWebServer, so app X wraps up the data as JSON and talks to app Y via http. Just as if it were talking to some server on the web, only it’s a local app.
Update 4 pm: Or not. I’m not sure it’s possible, or maybe just not allowed, to keep a network server running when the app is in the background.