This is a PWA App that tries to be online, full screen and never saves to a server (but it's totals are always available even after you close and open it)
It's solving a simple issue of a budget. You add it it throughout the month and at the end of the month it resets. You're able to see what you're spending this month and last. You don't get asked on what. it's simply a running total.
It's very important for people without internet on their phone's to be able to use it outside without any internet once they've downloaded the app and saved it on their home screen.
Example page: https://thedamian.github.io/moneywow/
Simply open the index.html on your browser or using something like Live-Server
Idealy you'd publish it for free using Surge.sh or Now.sh so you could use it on your phone.
You can even host it for free with Azure and AWS