The full web app is available at https://brianwendt.github.io/dndem/
From Brian Wendt:
I'm working on DnDEM as a way of learning the React.js framework while also building a helpful tool for myself and other DMs out there. Coding and Dungeons and Dragons are two of my biggest passions.
Please feel to send me feedback and and submit feature requests via the Issues tab. With some continued attention, I believe this project could grow into a goto tool for DMs wanting a clean, simple to use utility.
If you are interested in seeing what I'm working on, check out the Projects tab.