No moat. Still in business.

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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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Desktop data analysis app where you ask about your data in plain English and get Python code, charts and notebooks run on your computer.

Since 2017

Data and spreadsheets

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Build hosted or embedded checkout pages to sell products, subscriptions, tickets and services through your own Stripe account.

Since 2018

Free plan · Payments and checkout · Online sellers

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Open-source billing engine that meters usage, runs subscription and hybrid plans, and issues invoices for software firms.

Since 2021

Free · Invoicing and billing · Software companies

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An ecommerce platform with an API for selling products and subscriptions, with custom storefronts and checkout, for online brands.

Since 2021

Free trial · Online shops · Shops and retail

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Helps students sort courses, tasks, class schedules, flashcards and files into colour-coded folders.

Free · Focus and productivity · Individuals and families

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Records every AI agent decision in a signed, tamper-evident log so teams can show regulators what their AI did under the EU AI Act.

Free plan · Developer tools · Developers

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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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A note app for desktop and phone that records and transcribes, then answers questions using your own notes.

Notes and knowledge · Individuals and families

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Lets developers share live progress of scripts and jobs through a link, via an API or a tqdm replacement.

Uptime and monitoring · Developers

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Choose who can see each page on a WordPress site, with teasers, redirects and paywalls for subscription content.

Free plan · Communities and memberships · Creators and writers

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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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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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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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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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A reading and study app that lets you clip from books and papers, link the clips in mind maps and review them as cards.

Courses and learning · Individuals and families

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Learn Japanese or Korean by tapping words in YouTube videos, manga and books, with flashcards that track what you know.

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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Acts as merchant of record for software companies, handling subscriptions, usage billing, feature limits and global sales tax.

Pay as you go · Invoicing and billing · Software companies

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A WooCommerce plugin that lets shops sell subscriptions, repeat deliveries and instalment plans, with dunning and cancellation flows.

Payments and checkout · Online sellers

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Adds usage limits, credits, plans and spend controls on top of Stripe so AI startups can change pricing without rebuilding billing.

Free plan · Payments and checkout · Developers

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

Free plan · Courses and learning · Individuals and families

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Billing for SaaS and AI companies that handles subscriptions, usage metering, quotes and invoices.

Free plan · Invoicing and billing · Software companies

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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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Adds recurring billing, trials, split payments and subscription boxes to WooCommerce stores.

Free plan · Payments and checkout · Online sellers

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A reading app for language learners that imports books, articles and videos, translates words and sends vocabulary to Anki.

Since 2026

Free · Courses and learning · Individuals and families

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A WooCommerce plugin for selling subscriptions, taking recurring payments and tracking renewals for online stores.

Free plan · Payments and checkout · Online sellers

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Runs versioned SQL and Python database migrations with dry runs, history checks and rollbacks, for Python teams.

Since 2026

Free plan · Developer tools · Developers

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A language app where a partner or friend fills in words, audio and sentences for you to study, on iPhone and Android.

Courses and learning · Individuals and families

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Learn English words from books you are reading, with ready-made flashcards, quizzes and a word bank.

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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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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Hover over Chinese text in any Mac app to see pinyin, meanings and sentence breakdowns, and save words as flashcards.

Since 2026

Free plan · Courses and learning · Individuals and families

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Pools GPUs and CPUs from many cloud providers and your own servers so developers can run large data jobs in one place.

Since 2026

Developer tools · Developers

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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.

Free plan · Courses and learning · Individuals and families

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WordPress plugin for selling physical goods, digital downloads and subscriptions with built in checkout and payment gateways.

Payments and checkout · Online sellers

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Takes payments as merchant of record for software and AI products, with subscriptions, usage billing and tax handled.

Since 2025

Invoicing and billing · Developers

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Turns notes, PDFs or images into flashcards you can study online, share by link or print.

Free · Courses and learning · Individuals and families

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An app for learning Japanese with an AI tutor, speaking roleplays, kanji, quizzes and a personal study plan.

Since 2026

Free plan · Courses and learning · Individuals and families

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Makes subtitles for your video and audio files so language learners can look up words and send them to Anki.

Since 2026

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

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Self-hosted billing for web and game hosting firms that automates subscriptions and server setup, with a WHMCS migration tool.

Free · Invoicing and billing · Software companies

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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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Records lectures and meetings on Mac or iPhone, transcribes them locally and turns them into notes, flashcards and study sheets.

Free · Notes and knowledge · 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.

Free plan · Developer tools · Developers

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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.

Courses and learning · Individuals and families