tl;dr; Check out Budget Zen for all the links to all the platforms!
Basically now there's a free version for Linux and Windows, and the iOS, iPadOS, and Android versions are paid (once, and with family sharing enabled).
The web app is currently in beta, and requires a sync token to work, but I plan on eventually allowing it for free as well, because it runs entirely in the browser. The code for all of these apps is also available in GitHub!
Thank you for your attention and kindness. I really appreciate it!