While it's nice that you can use markdown, the absence of tags for organising things (and/or the absence of folders) makes this next to useless.
The integration with Firefox and the syncing with Android is a great idea but since the note-taking app itself is primitive it's hard to see a reason to use it.

So, keep the great syncing, add in tags and if you really want to conquer/liberate the planet add in copy/paste of images, i.e. screenshot captures and that's pretty much it, game over.

And what about a Search functionality, shouldn't this be a basic for any notes app ?

I know there are open issues on github for all of the above.

To be honest, if this wasn't done by mozilla/firefox I wouldn't have taken to time to comment, but you people do alot of good, nay great, stuff so you've gotten us used to far better quality than this.