Ambify can not only receive AirPlay audio but send it as well.
In System Capture mode audio can be sent to any AirPlay capable receiver such as AppleTV or AirPort Express.
When in AirPlay receiving mode, audio can be received and forwarded via AirPlay at the same time.
In order to output to an AirPlay device, bring up the audio settings and select your speaker from the drop down menu.
Note that in order to output AirPlay while capturing system audio the "Low Latency" option needs to be enabled.