Twitch has released a beta version of Twitch Studio, its streaming software, for Mac. Up until now, the software only worked on Windows.
Twitch Studio has desktop audio capture capabilities, hardware detection, green screen setup and lots of customisation options for streaming. iPhone and iPad screens can also be shared through this software and chat options are built right in.
The software is currently in beta but will receive new features throughout the year. You can download Twitch Studio from this website.