Preferably an application that you can sync and save. Not sure what alternatives are safe in terms of privacy and security.
If you have nextcloud and use linux: Iotas
It is really simple but suits my needs! Also looks great on the GNOME desktop.
I like Org Mode, but that’s sort of… Begrudgingly. I like any FOSS notes app better than any closed source notes app. That’s not even me having strong feeling about FOSS (which I do), it’s more about… I am very picky about note apps. Org Mode (with org-roam) does the best job of getting out of my way and letting me write and resurface notes.
Trilium is good
I use logseq with nextcloud, works even on Android, 0 issues so far.
QOwnNotes for me. Also such a catchy name. Seriously though, ignore the stupid name, just give it a try.
Zim
I tried most of what people have mentioned, but eventually found that MD files just worked best for me. So Nextcloud Notes became my default.
https://play.google.com/store/apps/details?id=it.niedermann.owncloud.notes
That’s my go to for my quick scratch pad notes, generally something I only need for a one time deal.
I use the Bit Warden secure note feature for more permanent things.
If it is a more ongoing documentation deal that needs organization I like Bookstack.
All depends on the purpose one uses it for.
Huh, hadn’t even realized I could do notes in BitWarden.
I migrated from Logseq to Trilium (on maintainance mode) because of the sync feature on server, so I access locally to notes on all my devices. The new project Trilium Next just released a beta version for testing, same UI but lot of changes on backend. It does not have a big plugin ecosystem but it’s powerful on itself.
QuillPad on Android and I don’t have a favorite on desktop yet
Believe it or not… Vimwiki (&& syncthing for synchronisation across my machines)
it’s rather no nonsense idk. I’m not even a vim wizard, I just know the bare basics
Cherrytree, no question. You can make hierarchical lists/notes, hyperlink to files, folders, websites and other nodes (lists). You can also insert tables and images in your entries and format text. The whole thing is saved as a single file and you can choose for it to be encrypted if you want. I sync it between devices using Syncthing. Both are FOSS, private and secure. Cherrytree’s UI doesn’t look especially modern but is very effective and you can make your own themes for it in the preferences if you want to glam it up a bit. You can pretty much use it as a wiki for your entire life. In fact, if I could only have one application on my computer it would be this!
Notepad++, local files
Fossify notes
Markor on Android, MarkText on desktop. I sort notes in category folders and use Syncthing to keep devices… well, synced.