With AI coding tools lots of people are having the same idea. Here is another one that uses sampled split flap sounds: https://www.minisplitflap.com
Anyway, here's one that I made with jQuery 10 years ago (since forked and now maintained by qrion) https://qrion25.github.io/splitflap/
In terms of features I haven't seen other split flap displays offer, it rolls a little better (more than one flap segment can be rolling at a time, letting the rolling animation be slower) it lets you set up a completely custom deck, and can even support muliple letters or numbers on a single flap (like the real displays sometimes do -- they might have the name of a whole train station)