Wow very impressed with the UX. Bravo!

It's cool you built it with dart but to me this is like saying "Check out this cool app I made, it created using php" Well it could be built with anything because when I look at the app all I see is the frontend. All your Dart is now minified JS, so it's no consequence to me if it was built with Dart or JS. Maybe you have a link to a Github repo where your Dart lives so I can admire the "dart" part of this title? Other then that, how was Dart? I almost worked on the Dart team and I have friends on the Dart team at Google so I am always curious to see what your experience with it was like.

Again Bravo! Lovely app!