MQTT on iOS
There are a couple of options for using MQTT on iOS. Facebook are doing so (they credit libmosquitto in their native Facebook iOS app, and in the Facebook Messenger app).
It is possible to use libmosquitto on iOS. Marquette is an example iOS app (with source) to control a Nanode.
There is also an Objective-C implementation of a client from the m2m.io team. This ships with an Xcode project which contains a simple iOS publish/subscribe client, HelloMQTT.
- mqtt-prowl - Subscribe to topics on an MQTT broker and notify via Prowl