No moat. Still in business.

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Lets teams edit, test and send transactional email templates without code deploys, with A/B tests and analytics.

Since 2014

Subscription · Transactional email · Software companies

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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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Email marketing app for sending newsletters, campaigns and automated sequences, built for teams that write together.

Since 2018

Free plan · Email marketing · Online sellers

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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 and A/B test pricing tables for your website without code, with Stripe revenue insights.

Since 2024

Free plan · Website builders · Online sellers

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Lets app and game developers change settings and run A/B tests remotely, without shipping a new build or waiting for store review.

Since 2024

Developer tools · Developers

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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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Collects traces, metrics and logs through OpenTelemetry for engineering teams, hosted or on your own servers.

Since 2022

Free trial · Uptime and monitoring · Developers

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Handles in-app subscriptions for mobile apps, with a paywall builder, price tests and revenue reports for app teams.

Free plan · Payments and checkout · Developers

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Build popups, multi-step forms, quizzes and on-site widgets to collect leads and sales from website visitors.

Free plan · Forms and surveys

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Records visitor sessions on your site and uses AI to point out errors, rage clicks and drop-offs, alongside heatmaps.

Free plan · Website analytics

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A WordPress plugin for top bars and popups with countdowns, coupons and signup forms, plus click stats and A/B tests.

Free plan · Marketing and social

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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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Turn app features on or off and roll them out to chosen users without redeploying, with unlimited team seats.

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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Application performance monitoring with logs, traces, metrics and alerts on OpenTelemetry, in the cloud or self-hosted.

Since 2022

Free plan · Uptime and monitoring · Developers

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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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Design, send and measure email campaigns and push messages, with a WooCommerce plugin for online shops.

Free plan · Email marketing

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Feature flag service that lets software teams roll out, test and switch off features in production without redeploying.

Subscription · Developer tools · Developers

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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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Students turn class notes or a PDF into a practice test that marks itself and explains each question they got wrong.

Since 2024

Free plan · 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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A no-code popup tool for shops and websites to collect emails, show offers and win back visitors about to leave.

Free plan · Marketing and social

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WordPress plugin for publishers to place, rotate, target and schedule ads from any network and track clicks.

Free plan · Marketing and social · Creators and writers

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A language app that translates words offline, saves them to your own tagged word list and helps you review them with flashcards.

Since 2025

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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WordPress plugin for building popups and bars with display rules, A/B tests and email signup capture.

Marketing and social

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WordPress plugin that pins a floating button to blog posts so bloggers get more clicks on offers and contact links.

Free plan · Marketing and social · Creators and writers

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Feature flags and A/B tests that read results from your own data warehouse, for software product teams.

Free plan · Website analytics · Software companies

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Add one script to your site for widgets like local pricing, exit offers and social proof to lift sales.

Since 2025

One-off payment · Marketing and social · Online sellers

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Cookie consent banners and consent records for websites and apps, so businesses meet GDPR and similar laws.

Free plan · Legal and compliance

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Lets marketing and design staff describe web app changes in plain English and get them as GitHub pull requests for engineers to review.

Since 2026

Free plan · Developer tools · Software companies

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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.

Since 2025

Courses and learning · Individuals and families

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

Since 2026

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

Since 2025

Free plan · 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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Feature flags and remote config so software teams can release to user segments, run tests and switch features off fast.

Free plan · Developer tools · Developers

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

Since 2025

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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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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Shows different text, popups or redirects to each WordPress visitor based on location, device or behaviour.

Free plan · Marketing and social