No moat. Still in business.

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Excel add-in for querying tables with SQL, scripting workbooks in C# and building custom Excel functions.

Since 2016

Free plan · Data and spreadsheets · Developers

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Drills you on keyboard shortcuts for editors and work apps with spaced repetition until they become habit.

Since 2012

Free plan · Courses and learning · Individuals and families

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Weather forecast and historical climate data over a simple JSON API, free for non-commercial projects.

Since 2021

Free plan · Developer tools · Developers

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Sends your notes from books, podcasts and articles back by email or Telegram on a spaced repetition schedule so you remember them.

Since 2024

One-off payment · Notes and knowledge · Individuals and families

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

Website builders

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

Free plan · Security and passwords

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Web analytics for sites and online shops, with real time stats, visitor behaviour and ecommerce reports.

Free trial · Website analytics · Online sellers

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An iPhone app that takes Japanese learners from beginner to fluent with one new sentence per flashcard and spaced review.

Since 2015

Courses and learning · Individuals and families

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Make your own flashcard decks and review them on a spaced repetition schedule in the browser.

Since 2015

Free plan · Courses and learning · Individuals and families

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A browser extension that saves and highlights words you look up on web pages, then drills them with flashcards.

Since 2020

Free plan · Courses and learning · Individuals and families

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Note app for students that builds flashcards, quizzes and summaries from notes and PDFs with spaced repetition.

Since 2021

Free plan · Courses and learning · Individuals and families

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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

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An API that serves current, forecast and historical weather for any location, for apps and weather-sensitive firms.

Since 2023

Free plan · Data and spreadsheets · Developers

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A REST API that gives current, forecast and historical weather for any location, plus severe weather alerts.

Free plan · Developer tools · Developers

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Flashcard app that uses spaced repetition so learners review hard cards more often, with sync between devices.

Courses and learning · Individuals and families

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Flashcard app for iPad and iPhone where students draw, type or add images to cards and review them with spaced repetition.

Since 2024

Courses and learning · Individuals and families

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A study app for students with spaced repetition flashcards, made from notes and PDFs, and scheduled around your calendar.

Free plan · Courses and learning · Individuals and families

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Spreadsheet that links to databases and files and lets AI write the formulas, Python and charts for you.

Since 2023

Data and spreadsheets

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A cloud workspace for creating, running and sharing marimo Python and SQL notebooks for data work

Since 2024

Developer tools · Developers

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

Since 2024

Courses and learning · Individuals and families

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Flashcard maker that schedules reviews by spaced repetition, with dictionaries and text to speech for language learners.

Since 2024

Free plan · Courses and learning · Individuals and families

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Learn to read Arabic with alphabet lessons, graded stories and flashcards that schedule reviews around your memory.

Since 2026

Free plan · Courses and learning · Individuals and families

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An iPad app that teaches children in grades K to 5 to spell new words using spaced repetition and a mock spelling bee.

Since 2026

Courses and learning · Individuals and families

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Upload a textbook and get chapter problems, feedback on your written answers and spaced recall reviews, for self-learners.

Since 2026

Free plan · Courses and learning · Individuals and families

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Students upload slides or notes and get practice quizzes and spaced-repetition flashcards made from them.

Since 2025

Free plan · Courses and learning · Individuals and families

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A flashcard app that makes study cards from your PDFs, articles and photos and schedules reviews so you remember them.

Since 2026

Free plan · Courses and learning · Individuals and families

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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

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Save new words from what you read or watch, get AI definitions and examples, then review them with FSRS flashcards on Apple devices.

Since 2025

Free plan · Courses and learning · Individuals and families

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Connect Claude or ChatGPT so they turn what you read into flashcards, then review them on any device.

Since 2026

One-off payment · Courses and learning · Individuals and families

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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

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An iPhone app that builds a short-lesson course on any subject you choose, with reviews, streaks and an AI tutor.

Since 2026

Courses and learning · Individuals and families

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Piano practice app that listens over MIDI as you play sheet music and schedules bar by bar memory reviews so pieces stick.

Since 2026

Subscription · Courses and learning · Individuals and families

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Turns PDFs and notes into flashcards you can review and edit, then export to Anki, Mochi or SuperMemo.

Since 2026

Subscription · Courses and learning · Individuals and families

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Reads your Anki flashcards aloud through headphones and grades your spoken answers, with an AI tutor for follow-up questions.

Since 2026

Free plan · Courses and learning · Individuals and families

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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

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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

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A web workspace where analysts write SQL over market prices, macro series and SEC filings, then chart the results without Python.

Since 2026

Subscription · Data and spreadsheets

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Helps developers prepare for coding interviews by rebuilding algorithm solutions from memory with spaced repetition drills.

Free plan · Courses and learning · Individuals and families

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Paste a YouTube link or upload a transcript and get an Anki flashcard deck made by AI, ready to import.

Since 2025

Free plan · Courses and learning · Individuals and families

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

Free plan · Website builders

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A flashcard app that schedules reviews with spaced repetition and can generate study decks with AI.

Since 2025

Free plan · Courses and learning · Individuals and families

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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

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Turns uploaded notes and slides into practice quizzes with daily recall and review so students are ready for exam day.

Since 2025

Free plan · Courses and learning · Individuals and families

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A flashcard and practice app that helps German learners remember whether a noun takes der, die or das.

Since 2026

Free · Courses and learning · Individuals and families

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An API that returns live and archived weather forecasts and actuals for chosen points, for apps that need weather data.

Since 2024

Free plan · Developer tools · Developers

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Write notes and flashcards in markdown, then review them on a spaced repetition schedule.

Since 2019

Free plan · Courses and learning · Individuals and families

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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