FlashStacksLearn a language in glances, not sessions
FlashStacks Learn is 5,100 ready-made vocabulary cards across five languages, sitting on your Lock Screen. You check your phone around a hundred times a day. That's a hundred chances to see a word you're trying to remember — without opening anything.
Five languages, sixteen topics each
Every language ships with 1,020 cards split into sixteen packs, so you start with the words people actually use rather than a blank deck.
- 🇫🇷 French — 1,020 cards
- 🇪🇸 Spanish — 1,020 cards
- 🇯🇵 Japanese — 1,020 cards, kana and kanji with romanisation
- 🇰🇷 Korean — 1,020 cards, Hangul with romanisation
- 🇨🇳 Mandarin Chinese — 1,020 cards, simplified characters with pinyin
The topics: greetings and basics, numbers, everyday objects, occupations, food and drink, family, time and calendar, weather, colours, clothing, health, transport, emotions, places, shopping, and nature.
No deck building, no setup
Tap a pack and it installs instantly as a real deck — no download, no waiting, because every card ships inside the app. From that moment it behaves like a deck you made yourself: edit cards, add your own, study it, quiz yourself, put it on a widget.
The Lock Screen is the whole point
Most language apps need you to remember to open them. FlashStacks puts the word where you're already looking. The Lock Screen widget shows the target word first with the English underneath, so you get the recall attempt before the answer — and a new word appears as often as you like, from every minute to every few hours.
See how the widgets work if you haven't set one up before.
Spaced repetition does the remembering
Learn packs run on the same SM-2-based scheduler as the rest of the app. Swipe a card right when it was easy, left when it was hard, and the ones you keep fumbling come back sooner while the ones you know fade into the background.
Learning English instead?
If your iPhone is set to German, Spanish, French, Italian, Japanese, Korean, Portuguese, Russian or Chinese, FlashStacks Learn flips around: the same sixteen topics, teaching English from your language — 9,180 cards in total.
Honest about what this is
This is vocabulary, not a grammar course. There are no conversation lessons, no speaking practice, no streak guilt-trips. It's the part of language learning that's pure memory work, handled by the thing in your pocket you check anyway. Pair it with a course or a tutor and it does the job it's good at.
Language learning — FAQ
What languages can I learn with FlashStacks?
French, Spanish, Japanese, Korean and Mandarin Chinese, each with 1,020 curated cards. If your phone's language isn't English, you also get English packs taught from your own language.
Do I need to build my own decks?
No. FlashStacks Learn packs are already written and ready — tap one and it installs instantly. You can still edit any card or add your own afterwards.
Is FlashStacks Learn free?
The language packs are part of FlashStacks Premium, which starts with a $2.99 first month on the annual plan. Building and studying your own decks is free forever.
Can I learn a language from my Lock Screen?
Yes — that's what it's built for. Set a Learn pack as your active deck and add the FlashStacks widget to your Lock Screen. The target word shows first, with the English beneath it, and the card changes at the interval you pick.
How often does the word on my widget change?
You choose, per deck: anywhere from every minute to every few hours. It's the Card frequency control on each deck's page.
Does it show Japanese, Korean and Chinese characters?
Yes, in the real script — kana and kanji, Hangul, simplified Chinese — with romanisation in brackets so you can read the card before you can read the writing system.
Is this better than Duolingo?
It's a different job. Duolingo teaches you a course; FlashStacks drills vocabulary into long-term memory using spaced repetition and the time you already spend glancing at your phone. Plenty of people use both.
Can I add my own words to a language pack?
Yes. Once installed, a pack is an ordinary deck — add cards, edit translations, delete the ones you already know.
Bonjour, every time you check the time
Five languages. 5,100 cards. No app to open.