Langvie - learn a language from the films you already want to watch
A language app that turns a film's subtitles into flashcards, so every word you study is one you will hear tonight.
- Role
- Founder · Lead Product Designer & AI Builder
- Timeline
- 2026 - now
- Platform
- Web app · iOS · Android
- Tools
- Claude Code · Supabase · Stripe
My husband and I watch films with subtitles to train our ears, and the films worth watching are full of words we don't know yet.
Stopping to look each one up kills the mood, and flashcard decks never worked for me because I never knew why I needed a word today. Langvie joins the two. It pulls the vocabulary out of the film you picked, keeps the line where each word is spoken, and lets you learn those words first. Then you watch without pausing.
Langvie is my own product. I designed it, built it with Claude Code, and market it myself.
From subtitles to a study plan
The app reads a film's subtitle track, keeps the vocabulary and one line of context per word, and discards the file. Those words become cards, and the cards feed a course that runs from beginner to upper-intermediate.
A dark interface lit like a cinema
Light comes from soft lamps behind glass panels, dividers are hairlines, and yellow appears only on the one action that matters on each screen. I tuned it over many rounds of looking at it on a real phone.
A web app first, native shells after
Langvie ships as an installable web app, then wraps into iOS and Android builds through Capacitor. Spaced repetition runs inside Postgres, so a phone and a laptop never disagree about which word is due.
Marketing in my own voice
Daily posts on Threads end with the same ask: comment a plus and I'll send the link. So interested readers come to me in the replies, and a vertical reel built in code explains the idea in under a minute.
Each screen hands the learner to the next one. The film page lists its most frequent words, and the card asks for one of them. The back of the card shows the line from the film where it was spoken.
- Aug 20, 2026
The first build
A web app that turns a film's German subtitles into swipe cards, with the spoken line kept on every card.
- Aug 21, 2026
The visual language settles
The palette moved from too black to too blue and back to dark first, blue second. The lamps, the glass and the single yellow action came out of those rounds.
- Sep 2, 2026
Streaks, a daily goal and a weekly league
League tiers are named after film genres, in the order a learner climbs them: Cartoon, Comedy, Drama, Thriller, Arthouse.
- Sep 30, 2026
Premium goes live
Most of the course and long AI conversations moved behind a subscription, sold through Stripe with an honest first-month offer.
- Oct 1, 2026
A pet that eats words
A word-eating monster hatches from an egg and grows when the learner studies, because the points it eats come from reviews.
- Oct 8, 2026
A modern memory scheduler
Word reviews moved to FSRS, the scheduler Anki uses today. The phone and the database run the same arithmetic, so the date on a button is the date that gets saved.
People learn from whatever they already watch and read, so the library grew past films. Every source feeds the same cards and the same review schedule.
A course with a clear next step
The course shows one current step, the units after it, and what each one asks: grammar, words, reading or a talk. A locked unit says what it is before the learner pays for it.
The news, rewritten for each level
Each Austrian news story is rewritten for every level with the same facts in the same order, and keeps one title a beginner can read. The article and its word list share one screen, so reading and studying never split apart.
Films, series, video and news
The library holds films, series, YouTube videos, news articles and word collections for real-life topics such as job hunting or a visit to the doctor. A learner can also bring their own materials or import an Anki deck.
The word-eating monster hatches from an egg, and feeding it costs the points a learner earns in reviews. Its food and water run down over a day, so a skipped day shows up as a hungry pet.
The monster grows from leaf to flame as the learner keeps studying.
Most of these decisions came from watching a real person get stuck, or from reading what competitors do and choosing not to copy it.
An honest paywall
The first-month offer has no restarting countdown and no invented social proof. A competitor's paywall I studied contradicted its own discount, which is exactly the trust problem to avoid.
A way out of every paywall
One learner told me she couldn't get past the paywall without paying, because its close button sat above the screen edge. So every paywall now has a visible cross and a Not now button under the price.
Nothing in front of the first lesson
The end of onboarding used to open a paywall. Now it opens the course, and the offer waits until the learner has felt the product.
League names a learner can climb
Film roles read as clever but not as a ladder, and metal tiers had nothing to do with film. Genres climb the way films get harder to follow: cartoons speak slowly, and arthouse makes no concessions.
Keep the words, discard the file
Subtitle files are parsed in memory and thrown away. Only the vocabulary and one short line of context per word are stored.
No account, no app
An early guest mode saved words in one browser under a promise that they sync everywhere. Removing it made the promise true.
Shipping fast with AI meant real learners met every decision within days, and their reactions set the next week's work.
My own pain was a narrow brief
Widen the brief past yourself
Langvie started as German from dubbed films because that was my problem. It grew into series, news, video and other languages once I looked at what people already watch and read.
A dark palette is easy to get wrong
Judge it on the device
The palette took many rounds, and each one was judged on a real phone. A dark screen on a monitor says little about the same screen in a hand in a dim room.
Paywalls tempt dark patterns
Sell the product, then the plan
Moving the offer after the first lesson and adding a clear way out kept the paywall honest. Under EU consumer rules, a countdown that restarts is also an unfair practice.
Two schedulers can drift
Run the math in one place, mirror it exactly
Due dates are written by the database and predicted on the phone with the same formula. I checked the two against each other until they matched exactly, before any learner saw a date.
