Yes, a simple RaspberryPi with Moode installed will allow you to stream any music service with Airplay from your iPhone. However, you may not require the Boss2 if you already have a DAC in your receiver or have an external separate DAC/preamp combo. I was able to setup UPnP and Airplay with the items listed below for a lot less.
1. https://www.amazon.com/Raspberry-Model-2019-Quad-Bluetooth/dp/B07TC2BK1X
2. https://www.amazon.com/Flirc-Raspberry-Pi-Case-Silver/dp/B07WG4DW52
3. https://www.amazon.com/CanaKit-Raspberry-Power-Supply-USB-C/dp/B07TYQRXTK
4. https://www.amazon.com/gp/product/B06XWN9Q99
5. http://moodeaudio.org
I would only consider the Boss2 if I required a DAC Hat on the RaspberryPi. Even then the shipping cost for the Boss2 is considerable.
1. https://www.amazon.com/Raspberry-Model-2019-Quad-Bluetooth/dp/B07TC2BK1X
2. https://www.amazon.com/Flirc-Raspberry-Pi-Case-Silver/dp/B07WG4DW52
3. https://www.amazon.com/CanaKit-Raspberry-Power-Supply-USB-C/dp/B07TYQRXTK
4. https://www.amazon.com/gp/product/B06XWN9Q99
5. http://moodeaudio.org
I would only consider the Boss2 if I required a DAC Hat on the RaspberryPi. Even then the shipping cost for the Boss2 is considerable.