I got sick of my dongle DAC getting caught and falling off in my pocket, so I designed and printed a bracket to fit perfectly on my phone! : r/headphones
iFi Audio: Portable „Hip DAC“: Stereo Magazine
Lightning DACs and Camera Adapters: How To Get The Best Sound From Apple Music Lossless - HIFI Trends
Amazon.com: Lavaudio USB-C Headphone Amp, Portable Desktop DAC 32Bit 384Khz CS43198 and Native DSD256 Hi-Res HiFi Headphone Amplifier 3.5mm/Type C/Lightning Out for PC/Smartphone Home Audio/ DS100 : Electronics
Help Guide | Connecting a smartphone
A closer look at the LG G5 Bang and Olufsen DAC
WYX Remix Android Smartphone Dock With 24 Bit High Performance DAC
Onkyo's music player is also DAC and headphone amp for your phone | Engadget