Pick a tool below to try it, or read the story behind it.
Go to updates ↓Learn and practise Spark SQL in the browser — ten short modules, then 34 business-framed exercises against a realistic warehouse, with a cheat sheet one click away.
Live수도권 지하철에서 어디에 서 있어야 빨리 앉을 수 있는지 알려주는 도구 — 출구가 아니라 좌석 기준. 한국어 전용.
LivePredicts what will trend in Korea next week and next month — an early-warning radar for creators hunting the next big thing. Fully in Korean.
Hold — 재검토 중Chess with a twist — ResetChess (moves snap back if legally possible) and TwoChess (two moves per turn) — play against a light AI bot.
LiveCompare US and Korean ETFs — overlap, duplicate holdings, fees, dividends, top-by-size rankings, style-based suggestions, and a Ray Dalio All Weather portfolio builder.
LiveOne shared "learn something today" board — a 5-minute, 1-2-3 read on a new subject each day, sourced from Wikipedia.
LiveA rolling live feed of world news from CNBC, BBC, and the Guardian — no login, no algorithm.
LiveRecord a few seconds of speech — get back a unique, installable font drawn from your voice.
LiveRecord your voice — get a personal RGB/hex color palette, refined with a 5-question preference survey.
LiveClick where it hurts (or pick a condition) and get general self-care info, common causes, and a clear sense of whether it's worth seeing a doctor.
LiveNew agents land here as they're built.
What is on my mind as I create this. Read my blog here.
SlowAcorn is a solo-built collection of small, free web tools — no company, no team, just one person shipping something new every so often. Each tool starts from a real question (where should I stand on the subway to get a seat? what does my voice look like as a font? how much do two ETFs actually overlap?) and turns into a small working app, built end to end and released for anyone to use.
There's no login, no subscription, and no data resold to anyone. A few tools use short-lived voice recordings that are deleted right after processing; the rest run on public data (Wikipedia, RSS news feeds, official Korean transit data, ETF holdings) refreshed on a schedule. Most tools are in English, with a few — like KoreanMetroSeat and Trender — built specifically for Korean commuters and creators.
New agents land here as they're finished. See the story behind the project or the privacy policy for details on what data (if any) each tool touches.