The events published by your core are HTML5 server-side events, so any framework that can talk to the modern web should be able to handle them. The easiest way to handle them is with a Javascript interface (web or stand-alone) but there are lots of other ways I am sure.
The code for the official iOS app from Spark is here, but it does not handle server-sent events.
Sorry I don’t have more for you–I wish I had more time to learn about how to do this on iOS too!