Simplenote devotee here. This looks very similar so I'm intrigued. I like that you are adding folders as well as tags.

Only thing I really lack for in Simplenote is:

- Ability to find notes that have a certain combination of tags.

- Command palette type search with cmd+o/cmd+p/cmd+k

- Ability to open multiple windows in Mac

- More keyboard shortcuts

- Images is nice, but I'm afraid they make frequent backups larger and larger and syncs slower and slower, unless they are just a reference to a CDN maybe? This was my experience with Ulysses and I had to delete my photo notes.