I use an AudioQuest Dragonfly Cobalt with iPhone when walking my dog. When sitting in my recliner, I use a Chord Mojo 2. Headphones are Sony WH-1000XM3 and Focal Clear. With the iPhone, you need the Apple Camera Adapter.
This is a good point. Dare I say, I use standard Apple earbuds when gardening or similar, since they’re practical, and I wouldn’t want to damage my IEMs or Mojo. Unfortunately, my DragonFly 1.2 doesn’t work with an iPhone without external power.
On a train or plane, or by the pool, I’ll use the Mojo with IEMs, and at home, headphones.
That iFi is a beast as far as reviews are concerned. Does come with a rather hefty price and it’s not as portable as you may think. You may get away with rubber-band-ing it to your phone
If you are looking for super easy portability and don’t want to worry about charging the DAC, I would suggest a Dragonfly or something similar from FiiO.
Whilst I do own a Dragonfly, I should say they’re overpriced, overhyped and measure poorly. But then again, I listen to music not measurements
On the other hand, my Mojo 1, whilst battery powered, sounds superb, is a little beast which can power many headphones and is not that big to carry around. The only downside is you will need to use its micro USB to USB A cable and that connected to the Apple CCK adapter if you have a newer iPhone such as the 13. On older iPhones I can connect it by just using a micro USB to lightning OTG data sync cable.