Long-time reader, first-time poster here.
I have not bought the app and only briefly looked at the video.
However, when I bought my first Apple Watch a few weeks ago, I wrote an Apple Shortcut, that pretty much creates a similar “App” using the WebKit engine of the Apple Watch.
It gives you three options (well, four):
1. Typing an URL
2. Search with Google
3. Choose from your bookmarks
4. Exit the “browser”

After visiting a web page and closing the browser window, the Shortcut automatically returns to the main menu, until Exit is chosen.
The bookmarks are saved in a list in the Reminders App.
For Setup, first create a new list in the Reminders App (choose any name. The default would be Web Bookmarks). Add a new item to this list for each bookmark (it is ok to just enter a dummy bookmark for now and add more later).
The title of the item is the bookmark name, the URL of the item is, well, the URL to the bookmarked website).
Any list item without a URL just returns to the main menu, this way one can for example add a “Back” item to the bottom of the list.

Next, install the Apple Shortcut. (Link below)
During the setup of the shortcut enter the name of the just created list (default: Web Bookmarks)

Done.
The Shortcut should show up as “Web Browser” in the Shorcut App on the Watch.
One can also set it as a complication on any watch face for immediate access.
It is probably less comfortable than the App in the article (it doesn’t have a browser history for example), but I am not charging a dollar for what is pretty much a WebKit wrapper

Also it DOES have a button to return to the previous website.

double tap on the address line, and you can reload a website, go back to the previous one, and toggle reader mode on/off.
I wrote this shortcut, mostly to test what is possible with the Apple Shortcut environment, and do not really use it.
However, I do appreciate feedback.
