Is this meant to be a cool tech demo, or a real product? I noticed the author mentioned adding new features and a premium version in another comment. This leads me to believe it's intended to be a real product.
With that in mind, I have a few questions:
1. If this is inspired by Notational Velocity, a very popular and real product, why is this also named Notational? I understand if you're doing a cool tech demo that it's not a big deal, but if you plan to charge money for this you probably shouldn't copy their name.
2. Was "Notational Velocity but real-time" your hypothesis of what would make this something people want to use/buy? If so, what about all the other very standard features that note-taking and thought storage apps have? Do you plan to hit baseline with those?
3. How do you compete with the larger companies who offer these apps for free to their users? Google Keep, Apple Notes, etc.
4. Is the real-time feature the only way you plan to make this different/better than the others?
I'm not trying to be a downer here, but I feel like I see "X app but real-time" posted to HN on a weekly basis now, like it being real-time is going to be the differentiator that makes it wildly popular. Those products then go on to ignore half the reasons why the others have users. Even if they reach feature parity, their one differentiator is "well, it's real-time". I'm not sure that's enough.
If this is just meant to be a cool demo of Vue.js (with an awesome homepage), well done, ignore my comments =)