My first target was https://github.com/AkashRajpurohit/clipper, a neat little clipboard manager. The owner was gratious enough to officially list my project under the "Clones" section of his readme =D The result was a 6mb file, compared to the original 165mb Electron app.
The second attempt was https://github.com/girkovarpa/temps-lite, an aesthetically-pleasing weather app which was motivated largely by the fact that the original was broken and abandoned yet still had people who wanted to use it. According to the open issues and forks trying to resurrect it, anyway. The file size savings were similar to the former, and they start virtually instantly. Unlike the Electron apps which have a bit of delay and then a blank window before they finish starting up.
There are a few working examples, and they have dramatically lower memory footprint and are quicker to start than full fat browsers.