Tagspaces is nice. Works the same on Linux, Mac, and Android (probably Windows and iOS too, I haven't tried). I like that it doesn't try to tackle note taking

Tagspaces is nice. Works the same on Linux, Mac, and Android (probably Windows and iOS too, I haven't tried). I like that it doesn't try to tackle note taking and synchronization. You can use dropbox/spideroak/btsync/owncloud/whatever-you-lik for that.