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 use Obsidian (which is free if you use Github to sync instead of paying for their syncing service) for prep and worldbuilding, as well as initiative tracking. I bought a laptop with a touch screen specifically for running games. Other than that, I’m all analog. Drawn maps, handwritten notes, physical dice and paper character sheets have my preference.