Flua is a language-learning app for adult beginners: a beginner course in each language, taught in sentence cards and built to be your main daily study for the first stage of a language. It builds one checked path through each language: every card teaches exactly one new word or pattern, and your memory decides when each one comes back.
Before you open the app, Flua has already chosen which words you'll learn, in which order, and inside which sentences. Every sentence is checked word by word against everything the path taught before it, so each card holds only words you already know plus the one new word or pattern it's teaching. Today each language has its beginner deck (1,008 to 1,058 cards per language, teaching 551 to 959 distinct words, 5 of 7 at Flua's A1 target of 700 or more), and the path keeps growing.
You hear a sentence, guess the underlined word, tap to check, and mark it Again or Good. There's nothing else to do. At half an hour a day, the French beginner deck takes about five weeks by Flua's working estimate, which comes from its founder's tracked study.
Each card's audio is expressive and natural-speed, with real rhythm and feeling, so your ear trains on speech the way people actually say it. You also see every sentence written.
Flua tracks your study time and your Again/Good history from the first session. Your Flua Index estimates the share of everyday sentences made entirely of words within your vocabulary.
Each card holds one new word or grammar pattern inside a sentence you otherwise understand. One unknown is a puzzle you can solve from context; two is a guess.
In corpus studies, the first 1,000 word families cover roughly 80% of everyday spoken language. Flua orders each path by how often words are really used, so your early hours go to the words you'll hear most.
Every word comes back on your memory's schedule, quick while it's new, then right before you'd forget: minutes, then days, then weeks. That's spaced repetition, and grading takes two buttons, Again or Good.
Flua is designed for you to reach your goal and move on. That's why the main way to pay is once: $89.99 for one language, including every future level published for it. Yearly and monthly plans exist for anyone who'd rather rent.
Flua publishes its combined study totals live on the transparency page, and your Flua Index can't flatter you, because one word beyond your vocabulary rules a sentence out.
| starting out | Adults starting French, Spanish, German, Italian, Japanese, Chinese or Korean from zero, or restarting after a class that didn't stick. |
|---|---|
| done with games | People who want their study time to go into the language, with no points, leagues or game-style lessons in the way. |
| flashcard users | Spaced-repetition users who'd rather follow a ready, ordered path than hunt for card sets and tune settings. |
| a goal ahead | A move, a job, an exam or a trip. Flua is built to be your main daily study for the first stage, the words and patterns people say most, with a tutor, your exam's materials or your field's terms alongside. Plans for each. |
| not yet for | Learners who already follow everyday speech, around B1: the current decks are below that level. The placement test in Settings shows where you are. |
| shows and films | Anyone who wants shows and films in their new language to stop sounding like noise. |
Flua was founded by Sora Kalden, a Carnegie Mellon computer science graduate. Flua is independent and bootstrapped, and isn't raising money right now; investors who want to talk are welcome to write to support@tryflua.com. It started with a trip to Japan: a month of Duolingo beforehand soon felt repetitive, so Sora went looking for how people actually learn languages fast. He found Anki's shared decks, and then a Japanese one built on one rule, one new thing per sentence, with lines and screenshots from real anime.
After the trip he studied that deck for thirty days, about half an hour a day, roughly 1,500 cards, and that is where most of his Japanese came from. With the lighter study during the trip, it came to more than 1,000 words and most basic grammar in about 20 tracked hours. That's one person's result, not an official test.
A year later he looked for the same kind of deck in French and found nothing close, so he built one. He has spent the two years since turning it into Flua, where every deck is held to that one rule and twenty other checks.
| start | Join the free beta on iPhone or Android, or start in your browser. No account is needed. |
|---|---|
| setup | In the app, pick your language and answer a few questions, such as your daily pace and whether you're brand new. Then you're on your first card. |
| help | Email support@tryflua.com. Replies usually arrive within a day or two. |
| a card looks wrong | Report it from the card itself, right in the app. |
| your data | The privacy page says what's stored and how to delete it. |
| name | Flua |
|---|---|
| type | Beginner language course for adults, taught in sentence cards with spaced review |
| website | tryflua.com |
| status | Available now; everything is free for the moment |
| platforms | iPhone, Android, web browser |
| languages | French, Spanish, German, Italian, Japanese, Chinese, Korean |
| level today | Beginner decks: 1,008 to 1,058 cards per language, teaching 551 to 959 distinct words, 5 of 7 at Flua's A1 target of 700 or more |
| stage | Public beta, free in the phone app while it runs |
| founder | Sora Kalden |
| team | One person |
| core method | One new word or pattern per card, most common words first, reviews scheduled by memory |
| free tier | First 150 cards, no account, no card details |
| pricing | $89.99 once per language · $39.99/year per language · $14.99/month for all languages |
| contract terms | Lifetime is a single payment. Yearly and monthly plans cancel anytime and keep access until the paid period ends. |
| support | support@tryflua.com, usually answered within a day or two |
| public data | Combined study totals, live on the transparency page |
Your first 150 cards are free, with no account and no card details, and anything you learn free stays free to review. While the beta runs, everything in the phone app is free. After that, one language costs $89.99 once or $39.99 a year, or all languages cost $14.99 a month.
French, Spanish, German, Italian, Japanese, Chinese and Korean. Each language has one path, with beginner material published today and more levels added as each deck grows.
Flua has no game-style lessons and no games. It builds one checked path through each language, where every card teaches exactly one new word or pattern inside a sentence you otherwise understand, and it brings each one back on your memory's schedule.
Flua puts understanding first: you learn to follow the language before you polish producing it. In the iPhone and Android apps, speaking cards then turn sentences around: you see the meaning and say the whole sentence, and you choose how much of each session goes to speaking. Everything you hear you also see written. Holding a conversation still takes practice with people.
For the first stage of a language, Flua is built to be your main daily study. Alongside it, add a tutor or conversation partner for speaking with people, the official sample papers if you have an exam, and your field's terms if it's for a job. Plans for a move, an exam, a job and a trip are at tryflua.com/plans.
Yes, on iPhone, Android and the web, and everything is free right now.
Flua was founded by Sora Kalden, a Carnegie Mellon computer science graduate who turned the method he used to learn Japanese into an app. Questions reach him at support@tryflua.com.