@Greg Be careful -- a significant number of bluetooth headphones/earbuds now require proprietary apps in order to do pretty basic things. I wouldn't exactly "recommend" PineBuds, but they work and have the promise of flashable firmware. Definitely plenty loud :) As a person who fundamentally doesn't like not being able to hear ambient sound, I also really like bone induction options.
@mlinksva @Greg I'm not actually totally sure having never bought a pair that required it, and the requirements seem only sketchily documented because everyone assumes you'd just be okay with an app. But I know when I was looking last year I saw things like needing the app to turn noise reduction on/off and to change sound profiles. Maybe also to only use one ear at a time (something I do frequently, see above about ambient sound). I don't think it's an issue in the < $50 range.
@johns @Greg curious, what basic things are there, besides being on or off (plugged in, or in case of bluetooth, connected)? I'm having a hard time imagining what an app would be for, but I'm sure people have come up with something now considered basic.
I have super cheap bluetooth headphones that work fine and don't have an app, but mostly use a usb-c-to-headphone-jack-with-wired-headphones when I need to use phone for audio because even a moment fiddling with bluetooth feels like work.