Not bad. I like some things, don't like others, but this is not important. What is important (beware, pessimistic comments):

1. Too slow. Too many server-side steps with slow page reload for an app that should be simple. Perhaps you should do more on the client without reloading, or get a better server code. Write it in a compiled/faster language.

2. I don't believe the world needs another note-taking app.