Typically I use pen and paper, but I've been interested in a tablet or similar device for a while and am interested in what other people are using.
The reMarkable 2 seems like a really cool option to play with, but also pretty pricey for trying it out to see if it would even work well.
While it's not directly related, when playing in games, I usually use a paper character sheet for reference, a notepad for consumables, story notes, and HP, and Pathbuilder on my phone for spells.
I've become so fond of Foundry's set of tools that I think at this point I'd prefer it over face to face. It just handles so many things.
If I ever do get into a face to face gaming situation again, I might look to see if I could have a set of tools on par with what it offers for handling dice, action order, telling me if something can be done or not, correcting me on my encounter building (too high or too low CR for example), and other tools.
That last one, correcting me on encounter building, is particularly useful with some adventure paths that are over tuned. Build the encounter with your actual party in Foundry with 'Monk's little details' mod and it will tell you what the actual challenge is by the rules, as opposed to what the module writer thought.
That seems to be an issue with older PF2E modules.
I played on Foundry for the first time at PaizoCon this year and was blown away by how polished I thought it was. The next day I ended up playing a game on Roll 20 and it was just nowhere in the league as the PF2e offering from Foundry, so I'm excited to get started using it. I finally got that part of my homelab spun up last night, so now I can finally start building out the short campaign I want to run for some old friends that have split up across the country.
They have a simply amazing mod / support team, and tons of friendly users that will go out of their way to make you feel welcome, at home, and supported.
Foundry can be used to run games in person quite well as long as you have a TV, or crappy projector or something. That's my plan for when I inevitably end up running a game face-to-face.
If you're willing to go the extra mile, there's a cool module under the Material Deck umbrella that allows you to roll physical dice into Foundry's dice roller, and use minis to control the tokens on the canvas.