Org-roam is kind of a wiki, you write your notes with all the formatting power of an org-file and you can link to other notes you have written.
Of course everything is searchable, with tags, without tags, however you want.
BUT: it takes time to get used to the shortcuts, and it takes a lot of time to configure everything how you like it.
The result is worth it.
Edit: I use Nextcloud to sync my notes accross my devices. On the smartphone there seems to be the App OrgNote available, but I haven’t checked it out, as I don’t use my smartphone that much.
There is always emacs with org-roam.
Org-roam is kind of a wiki, you write your notes with all the formatting power of an org-file and you can link to other notes you have written.
Of course everything is searchable, with tags, without tags, however you want.
BUT: it takes time to get used to the shortcuts, and it takes a lot of time to configure everything how you like it.
The result is worth it.
Edit: I use Nextcloud to sync my notes accross my devices. On the smartphone there seems to be the App OrgNote available, but I haven’t checked it out, as I don’t use my smartphone that much.