I was waiting for this question :)

I think it should be quite straight forward but it's more the deployment and maintenance I'm conscious of.

Mac and Windows (to an extent) both have app stores which can handle hosting, auto-updates, etc, though for Linux I'd have to build a bit of that myself. That also complicates platform specific dev / testing / deployment, and as this is a side project I'm conscious of time.

But if there's demand and things go well, I could be persuaded to release on another platform!

If the primary concern is the lack of a common packaging format/app store, please consider publishing to https://flathub.org/. It should solve these for you across all distributions.

Testing should also be simpler as most of your dependencies will bundled and testing in one distribution should suffice.

Alternatively https://appimage.org/

As a user, I much prefer AppImage – snap/flatpack feel like adding another app store to my system, while AppImage is just download and run.

The one I built is uglier, has fewer features, is single-user, but has a Linux download via electron or redbean!

https://github.com/filipesabella/CalcPad/

There is NaSC as well: https://parnold-x.github.io/nasc/

Good question, wanted to give it a shot but i only have linux...