Android

I use Obsidian.md, which starts as a note-taking app, but can end up as a whole knowlegde base. It has a built in core plugin for daily notes, but the plugin ecosphere will allow you to go way beyond that. It is free, however the built-in syncing is a subscription. You can just set up and use any sync service you want, it even has approved plugins for that, as the subscription is basically just a donation.

There is an open-source alternative called logseq, available on fdroid, i dipped my toes into that one for a while, but the plugins on obsidian like dataview and templater are just invaluable.

Check out Logseq!

I use Joplin for notes, though if you want daily notes specifically "Diary" might also be a good choice.

On Android, not much of anything. Who wants to type many notes on a screen keyboard? I use org-mode on a Debian laptop for that. If I want to take a note on my phone for some reason, I typically just send myself an email.

Try Diarium, it stores it's data in your choice of cloud sync, Dropbox, Google Drive etc rather than a cloud run by the program.

There's loads of options, for your writing, tags, photod, even hooks up to Strava if your do sportd, etc, it's a one time payment so no abonnement.

Before I had tried others, this is the best around, especially as it keeps your data private.

I use a text file with guake. I hit F12 and I can instantly update my notes. I change priority by moving stuff higher or lower in the file.

I tried logseq, but it was more effort than just typing.