100+ free client-side calculators, zero tracking — built solo, just open-sourced it

Hey IH — solo dev here (DevOps/backend day job), sharing something I've been building nights and weekends: tools-berry.com, about 100 small calculators and converters, all client-side. Paycheck/tax calculators for all 50 states + DC, unit and date math, image resize/convert, a handful of dev and text tools.

The part I actually cared about: most free paycheck/tax calculators either gate behind a signup wall, POST your salary to a server, or use stale/guessed tax numbers. I hand-sourced the 2025-2026 federal brackets, FICA, state withholding tables, and the new OBBBA changes from IRS pubs and state DOR docs, with the source cited right on the page. Nothing you type into a calculator leaves the browser — you can confirm it yourself in the network tab.

This week I open-sourced both repos (MIT):

• Full site: github.com/edyda99/tools-cherry (vanilla JS, no framework, Cloudflare Pages)
• Just the tax engines: github.com/edyda99/us-tax-engines (pure functions, zero deps, 1,700+ test assertions against the statutory numbers — if a number's wrong, that's where to check my work)

Business model is ads only, no paywall/upsell/email capture. Just shipped a feedback widget (D1-backed) so people can rate/comment on any individual tool page — that's the main thing I'm after here: what's broken, what's confusing, which numbers you don't trust.

Also just posted this on Show HN tonight if anyone wants to pile on there instead:
news.ycombinator.com/item?id=48951430

Thanks for reading — happy to answer anything about the stack, the tax-sourcing process, or the solo-dev-with-a-day-job logistics of it.