What tools would you like to see added to OnlineBox?

Hey! I'm the maker of OnlineBox — a collection of free browser-based tools where everything runs locally on your device. No uploads, no server processing, your files never leave your browser.

Currently we have tools for:

- Image compression, conversion and resizing

- CSV to JSON, JSON formatter

- Markdown to PDF with live preview and KaTeX math

- QR code generator, social card maker

- M3U8/HLS stream player

- PDF unlocker, folder to ZIP

- And more being added every day

I'm adding 1-3 new tools daily. What would you find most useful? Any workflows where you wish you had a simple, privacy-first browser tool?

All feedback welcome — this is still early and I want to build what people actually need.