Multi-language learning
Study the same word in English, Spanish, German and French side-by-side. See how Romance languages (Spanish, French) and Germanic languages (English, German) connect, discover cognates, and build polyglot skills from day one.
English · Español · Deutsch · Français
One word. Four languages. Zero subscriptions.
VocaStack is the privacy-first vocabulary app that teaches you English, Spanish, German and French side-by-side — so you see the connections between languages instead of memorizing them in isolation. Spaced repetition, streaks, and custom lists. Completely offline. Your data never leaves your device.
- 100% offline after install
- No ads · No tracking
- One-time purchase model
Most language apps make you choose one language — and pay every month for it
The usual routine
- One language per course, so polyglot learners juggle multiple apps
- Monthly subscriptions that quietly outgrow the price of a textbook
- Cloud accounts that harvest your study data for ads and analytics
- No internet, no studying — useless on flights and commutes
The VocaStack way
- English, Spanish, German and French studied together, side-by-side
- One-time purchase — no subscriptions, no recurring fees, no hidden costs
- Your learning data stays on your device; export it anytime
- Everything works completely offline after installation
Everything a serious vocabulary learner needs
Every feature below ships in the app — no upsells, no locked tiers.
Flashcards with context
Every word includes example sentences in all four languages, so you learn vocabulary in context — not in isolation.
Spaced repetition system
Review words at scientifically optimized intervals. The algorithm adapts to your memory, showing difficult words more frequently and building a personalized review schedule from your performance.
Progress tracking
Daily streak counter with freeze days, achievement badges at 10, 50, 100, 500 and 1,000 words learned, a learning heatmap calendar, and detailed statistics per language.
Custom word lists
Add your own vocabulary with translations — handy for travelers, exam candidates, and professionals learning industry-specific terms.
Complete control
Skip languages you don't want right now, set your own daily goals, and export your data anytime. VocaStack adapts to your learning style, not the other way around.
Completely offline
Learn on planes, trains, or anywhere without internet. No connectivity is required after installation — and no tracking, ever.
Light & dark themes
Light and dark themes that are easy on your eyes during long study sessions. (This page respects your system theme, too.)
See it before you install it
Real screenshots from the iPhone app: the four-language review card, the daily quiz, your progress, and the settings you control.
Why learn four languages at once?
1
Languages are related — use it
Spanish and French are Romance siblings; English and German share Germanic roots. Seeing all four together turns those family resemblances into memory hooks instead of leaving them undiscovered. Read our guide on cognates and language families.
2
Spaced repetition does the scheduling
You don't decide what to review — the algorithm does, at intervals tuned to your memory. Difficult words come back sooner; mastered words rest longer. Here's how spaced repetition works.
3
Momentum without manipulation
Streaks, streak freezes, badges and a heatmap calendar keep you motivated without dark patterns. Progress you can see, per language, every day.
4
A foundation of 100 words
You start with 100 carefully selected common words across all four languages — a practical base for beginners and intermediate learners, which you can extend with custom lists.
Built for learners who take vocabulary seriously
- Students preparing for language exams
- Travelers building practical vocabulary before a trip
- Polyglots learning multiple languages at once
- Professionals expanding business vocabulary with custom lists
- Privacy-minded learners who want their data to stay theirs
- Anyone tired of subscription-based learning apps
Frequently asked questions
Does VocaStack really work offline?
Yes. Everything works completely offline after installation. You can study on planes, trains, or anywhere without internet — no connectivity is required once the app is installed.
Do I have to learn all four languages?
No. You can skip languages you don't want to learn right now, set your own daily goals, and adapt the app to your learning style. The four languages — English, Spanish, German and French — are there when you want them.
Is there a subscription?
No subscriptions and no recurring fees. VocaStack uses a one-time purchase model: pay once, learn forever. There are no ads and no hidden costs.
What happens to my learning data?
Your learning data stays on your device. There is no tracking and no ads, and you can export your data anytime. VocaStack is designed privacy-first.
How does the spaced repetition system work?
VocaStack reviews words at scientifically optimized intervals. The algorithm adapts to your memory and shows difficult words more frequently, building a personalized review schedule based on your performance.
Can I add my own vocabulary?
Yes. You can create custom word lists and add your own vocabulary with translations — useful for travelers, students, and professionals learning industry-specific terms.
How many words are included to start?
VocaStack starts you with 100 carefully selected common words across all four languages — a foundation for beginners and intermediate learners. Every word includes example sentences in all four languages.