This sounds great. I would definitely love a splitwise alternative in particular!

You may want to think about using another name for your app suite though. Since it may bring confusion with the simple mobile tools (https://simplemobiletools.com/index.html) which for example also have a “Simple Notes” app.

Are you maybe using Windows? I’ve heard it can be slow sometimes, even on modern hardware.

I haven’t had any device that wasn’t recognized by Linux in 15 years. Do you have examples of hardware that “normal people” use and does not work?