I didn’t even know that Apple sold anything for $15 (Australian), let alone an absolute gem of a headphone amplifier, with super low output impedance that will drive common modern headphones with impedance’s under 100 ohms.
Listening right now with a set of KRK KNS 6400 headphones, 50 something ohms if I remember correctly. Phat clear bass.
Audio science review analysis:
As a few commenters noted, you could put that tiny device in a large box, and sell it as a high end DAC for over $100.
$15 Australian to destroy practically any on board motherboard headphone or line output. I got two. The USB A to USB C adapter so I can use it on my PC didn’t cost much less than the headphone dongle, and is slightly larger than the headphone amp!
A lot of manufactures of audio devices, especially headphone outputs ought to hang their heads in shame.