Maybe for a phone, maybe for a small tablet device.
Something (yeah, it's looking a purse...) that would stay at the waist, maybe have a shoulder strap... something manly though

that isn't a fanny pack (yuck it up, I'm American).
Small and out of the way. That's the point. But still allowing that device to be present and available.
Potentially even something that stay on the back could work.
Still thinking....
Almost like a tablet holster maybe....
I don't think anything would work. Those things are still too freaking big.
Belt clip.... Something that stays under the arm, just above the waist....
Hm...
https://www.satchel-page.com/products/map-caseBut not $300.
Maybe a map case then....