I've used a spreadsheet with the same basic functionality as this for years and it worked just fine. The main problem with it was when folks asked me to share it with them the spreadsheet wasn't exactly user friendly. Putting it in web app form makes it easier to identify which fields are meant to be edited and ensures that the formulas aren't accidentally changed.
The web app can be used without an account just to experiment and plug some numbers in. My hope is that it can still be useful to folks that'd prefer not to save their data just to get some rough insights and perhaps be a starting point for developing their own custom spreadsheets.
The web app can be used without an account just to experiment and plug some numbers in. My hope is that it can still be useful to folks that'd prefer not to save their data just to get some rough insights and perhaps be a starting point for developing their own custom spreadsheets.