Building a free calculator suite focused on UX instead of ads

I’ve been building a free calculator suite called NeatCalc in my spare time.

One thing I noticed: most calculator websites are overloaded with ads, cluttered layouts, popups, or poor mobile UX.

I’m not trying to reinvent calculators - mostly focusing on speed, clarity, accessibility, and making common calculations less annoying to use.

Also experimenting with using AI as part of the development workflow, which has been surprisingly helpful for prototyping and iteration speed.

Curious what small UX details people immediately notice in utility websites/apps.