Learn Languages,One Word at a Time
Lumina uses FSRS — a modern spaced-repetition algorithm — to bring every word back the moment before you would have forgotten it. 4,239 hand-curated words, 14 languages in any pairing, from A1 to C2.
Reviewed Right Before
You Forget
Lumina schedules every word individually using FSRS, a modern spaced-repetition algorithm that models how strong your memory of each specific word is — and predicts when it is about to fade.
New Word
A word arrives with its translation, and its pronunciation if the script needs one.
You Grade It
Again, Good, or Easy — by tapping or swiping. Each button shows when the word returns.
FSRS Schedules It
The algorithm models how strong your memory of that exact word is, and picks the day it is about to fade.
It Sticks
Struggle and it comes back sooner. Nail it and it disappears for weeks, then months.
Four Ways to Be Tested
Reviews arrive in four different forms, so you are recalling rather than recognising. Every word can be spoken aloud in a native voice.
Flip Card
The classic. See the word, recall the meaning, flip.
Multiple Choice
Pick the right translation from four.
Typed Recall
Type it out — the hardest and the most effective.
Listening
Hear the word and answer without seeing it.
4,239 Words, Sorted by Level
The whole library is hand-curated and sorted into six CEFR levels, A1 through C2. Every word is disambiguated where it needs to be — “bank” as in money and “bank” as in river never get confused with each other. Not sure where you are? Take the quick placement test and get placed automatically.
Placement Test
Not sure where to start? A short placement test puts you at a CEFR level from A1 to C2 — so you're not wading through “hello” if you already speak the language.
Any Pair, Either Direction
Pick the language you know and the one you want — 182 possible pairings, not a fixed list of courses. Progress is tracked per concept, so switching pairs costs you nothing.
Tricky Words
Words you keep forgetting get flagged automatically and collected into their own drill. One-tap undo puts a card back if you grade it by mistake.
Extra Depth for English
Studying English gives you more on every card: a natural example sentence in the right sense, the part of speech, and IPA pronunciation — for all 4,239 words.
Word of the Day
A home-screen widget and an optional daily notification, so a word finds you even on the days you never open the app.
Progress, Honestly
A year-round activity heatmap, a forecast of reviews coming up, accuracy, time studied, longest streak, and a browsable list of every word you have met.
Works Offline
The entire word library lives on your device. Study on a plane, in a tunnel, anywhere — it syncs when you are back online.
No Ads. No Purchases.
Nothing in Lumina costs money and nothing in it tries to sell you anything. No location, no contacts, no advertising trackers — and you can wipe your account in one flow.
14 Languages.
182 Pairings.
Choose the language you already know and the one you want to learn — any combination, in either direction. Not a fixed list of courses.
Changing your pair later costs you nothing. Progress is tracked per concept, not per translation, so a word you already know stays known when you switch. Languages with a different script come with a pronunciation guide built in — pinyin for Chinese, romanization for Japanese, Korean and Hindi.
English
The world's most widely spoken language — and the one Lumina goes deepest on, with example sentences, part of speech and IPA on every card.
Hebrew
Ancient language, modern necessity. Full right-to-left text support, in the content and across the whole interface.
Spanish
Over 500 million speakers worldwide. One of the most beautiful and accessible languages to learn.
French
The language of culture, cuisine, and diplomacy. Unlock a world of elegance and opportunity.
Portuguese
Spoken by 250 million people across four continents. Warm, rhythmic, and wonderfully rewarding to learn.
Chinese
The world's most spoken native language. Every word comes with pinyin, so you are never stuck staring at characters you cannot sound out.
Hindi
Spoken by over 600 million people. Devanagari script with romanization built in, so pronunciation is never a guess.
Arabic
A language of rich history and poetry, spoken across the Middle East and North Africa. Full right-to-left support included.
Indonesian
The wonderfully phonetic lingua franca of the vast Indonesian archipelago. A perfect entry to Austronesian languages.
German
The language of precision and philosophy. Open doors to Europe's largest economy and cultural powerhouse.
Japanese
A unique language with a complex writing system — and a romanization on every word so you can always sound it out.
Korean
Ride the Hallyu wave! Learn the language of K-Pop, K-Dramas, and a thriving technological hub — Hangul with romanization built in.
Russian
The most widespread language of Eurasia. Unlock the works of Tolstoy and Dostoevsky in their original form.
Italian
The language of art, music, and gastronomy. One of the most melodic and expressive languages in the world.
6 Games That
Actually Count
Games are not filler here — playing them feeds your real study data. Words you miss in a game get scheduled for review.
Word Sprint
How many can you get in 60 seconds? Your best score is tracked — challenge yourself every session.
Match Pairs
Pair words with their translations against the clock. Fast-paced and addictive — the ultimate vocabulary speed test.
Word Scramble
Rebuild the word from shuffled letters. Great for reinforcing spelling, recognition, and letter patterns.
Echo
Listen and identify. No text on screen — just a native voice and your ear doing the work.
Spelling Bee
Hear it, spell it. The toughest test of all — sound to letters with nothing in between.
Daily Challenge
The same word set for everyone, every day. Play it once, then compare your score with your friends.
See Lumina
in Action
A clean design built for focus. No clutter, no distractions — just you and your words.
‹ swipe to explore all 5 screens ›
Start Learning
Today
Lumina is distributed as a direct Android download — no store, no account with anyone else, no waiting. Build real vocabulary that sticks, completely free.
Free forever · No ads, no purchases, no subscriptions
Download the APK
Tap the button above on your Android phone. The file lands in your Downloads folder.
Allow the install
Android will ask permission to install from this source — the standard prompt for any app outside the Play Store.
Open and sign in
Pick your language pair, take the placement test, and start your first session.
The APK is served directly from this site over HTTPS. Lumina collects no location, contacts, camera, microphone or advertising data, and you can delete your account and every trace of it from inside the app at any time.
Before You
Install
The things worth knowing about an app you download directly.
Reasons to Come Back
Tomorrow
The best moment to review a word is the moment just before you would have forgotten it. Everything else in Lumina exists to get you to open it that day.
Streaks
Count the days in a row. Buy a shield to survive a missed day, or repair a broken streak if you slip.
XP & Levels
Climb from Wanderer to Cosmic — ten titles apart — with a celebration each time you level up.
Lumens
The in-app currency, earned by studying and winning. Spend it in the shop on card backs, name flair, streak shields and XP boosters.
Daily Quests
Small goals each day, with rewards for finishing them — enough to get you to open the app.
Achievements
A trophy case that fills as you hit milestones, from your first word to your longest streak.
Climb the Leagues
Five tiers, reset every week. Up to 20 learners in your bucket.
Learn With Other People
Friends are found by code, never by scraping your contacts — and the only thing you have to make public is a display name you chose yourself.
Friend Codes
Share an eight-character code. No phone numbers, no contact scraping, no email lookups.
Nudges
Poke a friend who has gone quiet and pull them back into their streak.
Duels
Challenge a friend to the same 30-word sprint and see who scores higher. Both of you play in your own time, within 48 hours.
Leagues & Contests
Every week you land in a bucket of up to 20 learners at your tier. Finish top five and you go up, bottom five and you drop. Weekly XP contests pay out in lumens.