No moat. Still in business.

0

Runs automated tests against your APIs and websites after each deploy and on a schedule, with alerts on failure.

Since 2016

Uptime and monitoring · Developers

0

Flash card app for learners to keep their own word lists and practise them with spaced repetition on Apple devices.

Courses and learning · Individuals and families

0

Desktop app for designing, calling and documenting APIs that keeps an OpenAPI spec in sync, offline with no login.

Since 2024

Free trial · Developer tools · Developers

0

Fixes the mixed content and insecure content warnings a WordPress site shows after it moves to HTTPS.

Website builders

0

Video player for language learners that shows two subtitle tracks at once, generates subtitles and translates them live.

Free · Video and audio · Individuals and families

0

Gets and renews free Let's Encrypt SSL certificates on cPanel shared hosting without command line work.

Free plan · Security and passwords

0

Mobile app where learners practise speaking a new language with AI characters and get pronunciation scores.

Since 2024

Courses and learning · Individuals and families

0

Ad-free app that teaches children aged 3 to 14 one of 19 languages through listening, speaking and reading along.

Since 2024

Free plan · Courses and learning · Individuals and families

0

Browser extension that swaps sentences on the pages you read into the language you are learning, scaled to your level.

Since 2024

Subscription · Courses and learning · Individuals and families

0

Teaches English, Spanish, French and other languages through song lyrics, with spaced repetition for new words.

Since 2024

Courses and learning · Individuals and families

0

Helps intermediate language learners reach fluency through spoken chats with an AI tutor, corrections and daily articles.

Courses and learning · Individuals and families

0

Listening drills that help language learners catch spoken numbers, phone numbers and clock times in over two dozen languages.

Courses and learning · Individuals and families

0

Practise a new language by chatting with AI, tapping words to save them and reviewing them later with spaced repetition.

Since 2025

Free plan · Courses and learning · Individuals and families

0

Builds a command line tool for your API from its docs, with binaries, install scripts and updates, so AI agents can use it.

Since 2026

Developer tools · Developers

0

Spin up hosted mock servers from OpenAPI, SOAP, GraphQL or gRPC specs so teams can test without the real backend.

Since 2025

Free plan · Developer tools · Developers

0

A browser extension for Chinese learners that puts words from your level into English pages, with readings and meanings on hover.

Since 2026

Courses and learning · Individuals and families

0

Phone app for learning a language by listening to native podcasts with synced transcripts and tap-to-translate words.

Since 2025

Subscription · Courses and learning · Individuals and families

0

Graded Japanese stories at your JLPT level, with tap-to-define words, grammar notes, audio and flashcards.

Since 2026

Subscription · Courses and learning · Individuals and families

0

A Chrome extension that translates X and Reddit posts and quizzes you on new words, for people learning English.

Since 2026

Subscription · Courses and learning · Individuals and families

0

Translates words and short phrases with examples and pronunciation, then saves them to a personal list for language learners.

Since 2026

Courses and learning · Individuals and families

0

A local desktop editor for writing language courses with lessons and self-marking exercises, plus a free app to study them.

Since 2026

Free · Courses and learning · Creators and writers

0

Short Spanish stories pitched at the words an A2 to B1 learner already knows, with unknown words brought back for review.

Since 2026

Free plan · Courses and learning · Individuals and families

0

An app for practising spoken conversations in 10 languages with an AI partner, then chatting with native speakers with translation.

Since 2026

Free plan · Courses and learning · Individuals and families

0

Compares your OpenAPI spec on each pull request and blocks merges that would break the services using your API.

Since 2026

Free plan · Developer tools · Developers

0

Live voice lessons with an AI language tutor that corrects mistakes as you speak and remembers your past sessions.

Since 2026

Free trial · Courses and learning · Individuals and families

0

Upload an OpenAPI or Postman file to get a chat agent that lets your users run your software's actions in plain language.

Since 2025

Free plan · Developer tools · Software companies

0

Language learners listen to free public domain audiobooks while following highlighted text and optional translations.

Free · Courses and learning · Individuals and families

0

Learn any of 75 or more languages from almost any starting language, including rare ones, with a school option too.

Free plan · Courses and learning · Individuals and families

0

A language learning app for 77 languages where every lesson ends with you saying the sentence aloud and getting feedback.

Since 2026

Free plan · Courses and learning · Individuals and families

0

Generates API docs, client libraries in ten languages and an MCP server from your OpenAPI file, plus usage monitoring, for API providers.

Since 2026

Free plan · Developer tools · Developers

0

Learn the 2,136 jouyou kanji by grade, with stroke order, components, readings and example words.

Since 2026

Courses and learning · Individuals and families

0

Keeps API specs, mock servers, tests and published docs in step from a single spec, for software teams.

Since 2026

Free plan · Developer tools · Developers

0

Point any domain at any URL with automatic HTTPS, path rules and hit analytics, no server to run.

Free plan · Website builders

0

Deploys apps from a GitHub repo onto a server in your own cloud account, with HTTPS and redeploys on each push.

Since 2026

Free plan · Developer tools · Developers

0

Mac app that pauses your shows and podcasts after each sentence to explain the translation, words and grammar.

Since 2026

Free plan · Courses and learning · Individuals and families

0

Language learning app where you add the words you need and it builds practice sessions around them, in 20+ languages.

Since 2025

Free · Courses and learning · Individuals and families

0

Turns an OpenAPI file into hosted API docs, client SDKs and an MCP server for software companies.

Developer tools · Developers

0

AI language teacher that runs group or private lessons with homework and practice talks in nine languages, for learners.

Since 2025

Free plan · Courses and learning · Individuals and families

0

A Chrome and Edge extension that translates words you select on any page and brings them back later so you learn them.

Since 2024

Free plan · Courses and learning · Individuals and families

0

Watches live API traffic so engineering teams can see usage, catch problems and enforce API standards.

Uptime and monitoring · Developers

0

Sets up and manages your own cloud server to deploy Django apps, with a dashboard, CLI and API.

Since 2021

Free plan · Developer tools · Developers