The Most Useful Site in the World🏠I want to figure out my mortgage, rent, or a loan6 tools
How much per month? How long? What is the real cost over the life of the loan? Includes early-repayment savings.
💼I want to check my salary, tax, or take-home pay4 tools
UK, US, and general income tax — plus overtime, bonuses, and the difference between gross and net.
🛒I want to compare prices, deals, or unit costs15 tools
Multi-pack maths, energy tariffs that flip rank at certain usage, true cost-per-use.
💰I want to budget, plan, or forecast my money7 tools
Monthly budget, sinking funds, invoices, cashflow, pay-yourself-first splits.
📏I want to convert a measurement, weight, or currency18 tools
Universal converter, currency, paper, ring, bra, shoe, and the awkward ones nobody else has.
📈I want to calculate compound interest, savings, or an investment6 tools
Future value, present value, retirement projections, and the magic of compound growth visualised.
🔐I want to build or test a password, hash, or secret1 tools
Generate passwords, hash strings, encode/decode base64, decode JWTs, generate UUIDs.
🧑💻I want to format, validate, or debug JSON or code1 tool
JSON, regex, YAML, SQL, CSV — linters, prettifiers, validators, and explainers.
🩺I want to check or improve my BMI, calories, or macros9 tools
BMI, TDEE, calorie targets, macro split, water intake, ideal weight — and what the numbers actually mean.
🏃I want to plan a run, race, or training week4 tools
Race pace predictor, training zones, splits, VO2 estimates, hike planning — and the honest Riegel formula.
🫁I want to sleep, breathe, or feel calmer14 tools
Breathing exercises, grief support, anxiety, sleep, lucid dreaming, grounding.
🐠I want to take care of my aquarium10 tools
Volume, stocking, CO₂, lighting PAR, water chemistry, nitrogen cycle — the day-to-day of a planted tank.
🐕I want to take care of my dog10 tools
Calorie portioner, training, life-stage, breed health — caring for the dog without the marketing.
🔭I want to look at the stars or the moon7 tools
Telescope eyepieces, lunar phases, deep-sky exposure, redshift, dark-sky quality.
🦅I want to identify or appreciate a bird10 tools
Bird ID, song mnemonics, life list, feeder nutrition, optics — for the birder with or without binoculars.
🍳I want to cook, bake, or brew something11 tools
Coffee ratios, sourdough hydration, sugar stages, candy temperatures, brining, sous vide.
🇯🇵I want to learn Japanese9 tools
Hiragana, katakana, kanji, JLPT vocabulary, keigo, particles, verb conjugations.
🗣️I want to learn French, German, Spanish, Korean, or Chinese8 tools
Verb conjugators, pronunciation, case systems, tones, and the bits the textbook skips.
✍️I want to write a cover letter, resume, or email3 tools
Cover letter, resume, business writing, emails, memos, proposals — and the proofreading that follows.
🤖I want to work with AI or LLMs10 tools
Token counts, prompt injection defence, MCP testing, embeddings, cost/latency matrices.
🕹️I want to use a Second Life or virtual-world tool7 tools
Region map, marketplace search, texture alignment, currency exchange.
🎵I want to make music or work with audio14 tools
BPM tap, tuner, metronome, scales, chord builder, audio tone generator, Morse code.
🎌I want to watch, plan, or read an anime10 tools
Binge-watch calculator, filler guide, cosplay prop scaler, con budget, character archetypes.
🌱I want to relax, plan my day, or be more productive13 tools
Habits, planners, sleep, mindful minutes, household emergency plan, declutter.
🌿I want to look up a herb, remedy, or acupressure point9 tools
Adaptogens, herbs, acupressure points, tincture ratios — with the disclaimers traditional-medicine content needs.
🎮I want to play, watch, or simulate something for fun10 tools
The arcade category: simulators, sandboxes, and toys that don't take themselves too seriously.
🖼️I want to generate or manipulate an image8 tools
Generative art, pixel painters, kaleidoscopes, mandalas, 3D spirograph.
🛠️I want a tool for the household (paint, tile, fence, garden)7 tools
Coverage calculators, material estimates, paint per coat, tile per square metre, fence post spacing.
✏️I want to write better, faster, or just spell things right6 tools
Spell-check, grammar, proofreading, readability, reading time, paraphrasing.
📊I want a productivity or business tool for my SaaS4 tools
Subscriptions, MRR, churn, invoice generators, the boring-but-essential business maths.
➕I want to learn or teach maths (calculus, algebra, probability)13 tools
Step-by-step solvers, formula references, visualisations for the parts of maths that look scary in a textbook.
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