GoodTools - Mini tools

A pocket toolbox of clever mini tools — notes, calculators, converters, prime & π math, an emoji board, and more. Free, fast, and works offline.

GoodTools — a toolbox that fits in your pocket.

GoodTools gathers dozens of handy mini tools in one clean, fast app. No clutter, no accounts, no sign-up — just open the app and grab the tool you need. Everything runs on your device, offline, with a friendly grid layout and full dark-mode support.

Everyday tools

Note — a scratchpad that saves as you type, so your thoughts are never lost. Calculator — a clean circular-key calculator for quick sums anywhere. Temperature Converter — drag a vertical slider from −30 °C to 120 °C and read °C and °F side by side instantly. Time — a beautiful always-black clock showing the current time to the second; rotate the digits to fit your screen. Emoji Board — a grid of hundreds of the most-used emoji and special characters; tap any one to copy it. Math & science tools

Factorial — exact n! for any number up to 1000, shown in full digits (no scientific notation). Factorizer — instant prime factorization of numbers up to 10,000,000. Prime Checker — check huge numbers (up to 20 digits) for primality and browse the following 30 numbers with live prime markers as you scroll. Pi 10000 — browse the first 10,000 digits of π in a scrollable, copyable view. Constants — a quick reference of the most useful math and physics constants with values and units. Random Number — tap for a fresh random number between 1 and 100. Fun & playful tools

Year Progress — see how much of this year has already passed, with the percentage ticked every second. Vibrate — press and hold the screen to feel continuous haptics, release to stop. Cube — a 3D cube you can spin and tumble with your finger (iOS 18+). Toss Coin — tap anywhere to flip a 3D coin high into the air with realistic spins and a satisfying landing buzz; check ○ or × (iOS 18+). Clean by design

All tools open from one tidy 4-column grid — no endless menus. Native look and feel with smooth animations, haptic feedback, and accessibility labels. Optimized for iPhone and iPad, light and dark modes. Private by default GoodTools collects no personal data. Notes and settings stay on your device, and the app works completely offline.

If you love GoodTools, please leave a rating — it helps more people find it. Ideas or problems? Write to us at feedback@luanlujizhi.com and we’ll get back to you.

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