Like I said before in another comment, there's only so much I can fit in a Hacker News title. :) I'd like to think that a lot of people use the term "a cross-platform app" to mean "an app that works on Android and iOS" though. Or "an app that works on more than one platform using shared code".

That being said, Flutter does have unofficial Linux and MacOS desktop embedders: https://github.com/google/flutter-desktop-embedding

I haven't had the time to look into it, but having seen a couple example Flutter desktop apps, it seems really promising!

I was able to get flutter to run in Windows, using this https://github.com/ds84182/flutter_sdl (so thank you ds84182 - whoever you are :))

but had to do some hacks. At the end I had flutter_sdl.dll (~10-15mb, depending how you compile it), and was able to add flutter_gallery (among other things).

Things that are missing - keyboard input, but there is a very hihg-level plugin system how to achieve this. Just haven't had the time to do it.

Tried implementing mousewheel, by simulating pad touches - but it ain't the same. Feels kind of obvious now, why it's not the same, but generally the controls themselves need to know about mousewheel. For example a gauge-like spinner can't be emulated this way.

Still very snappy, and someone on the flutter-dev mailing list mentioned that he, or she got live reloading.