Everything in the catalog

Block and JavaScript editor for building retro games that run in the browser or on handheld hardware.

Full-stack music learning web app featuring interactive guitar/piano tools and AI-assisted audio analysis (chord detection + vocal/instrumental separation)

Privacy-minded resume builder with AI help and portable, customizable output.

Packs the string literals of a JavaScript module into an XOR-encoded table without eval, for Cloudflare Workers.

Builds a full complementary color palette from one base color with brightness adjustment.

Uses the computer's audio input as an oscilloscope, FFT spectrum analyzer and signal generator.

CC0 unit converter covering 624 units across 28 types.

Checks how strong a password is and gives quick feedback on its robustness.

Suggests meals from your dietary preferences, calorie target and allergies using templates plus AI recommendations.

:guitar: Music Theory in Code.

Open source audit that checks 39 factors of SEO and whether AI assistants would cite a site.

WYSIWYG GitHub-flavored Markdown editor that looks like GitHub's rendering and supports HTML in Markdown.

Estimates return on investment from buying a home versus renting.

Edit a page's search and social metadata in one place, then export it as plain HTML or as code for Next.js, Astro, SvelteKit or Nuxt.

Routes white keys from midi-input to chosen scale to midi output

A JavaScript library for displaying notes on a music staff.

An ink & matte style productivity app

Generates strong passwords from simple memorable actions so they need not be written down.

Scans a website with Lighthouse and reports SEO, performance, accessibility and technical issues.

Simple Greek VAT calculator for adding or removing the tax (Greek interface).

Meditation timer with preset durations, guided instructions, ambient sounds and session statistics.

Estimates the savings goal and earliest age you can retire early.

Real-time word and character counter with a dark cosmic theme.

Logic gate simulator with drag-and-drop gates and wires built in React.