FlashBoss Vocabulary BuilderLearn vocabulary as fast as possible with spaced repetition and boss fights. Learn Spanish, German, or Esperanto as a full 3,000-word course — or sharpen your English with Adept (included free), German Roots, or Norman Roots (new DLC). No note-taking, no busywork — just read, listen, repeat, rate, fight! 3 free 1000 word card sets included. No subscriptions, no ads.How It WorksFlashBoss teaches vocabulary in context. Every card is built around a target word with one or more example sentences you can follow — grammar, collocation, and usage shown in one line. Rate each flashcard from 0 to 5. Spacing follows Fibonacci intervals — the better you know a word, the longer before it comes back. Words are grouped into thematic clusters, and each cluster is gated by a boss fight: a see-sawing battle where correct answers drive you forward and mistakes push you back. Win, and the cluster graduates. Your deck gets smaller over time.The word lists are themselves are frequency-selected, and weighted for usefulness: The most efficient words, arranged in the most efficient way we could conceive, so you can read thousands of words of example sentences, and learn context without feeling lost.Maintain your daily streak to earn Drive — banked days off for when life interrupts. Five to thirty minutes a day depending on your choice of master.Learn a Foreign Language — DLC Packs ($4.99 each)Full 3,000-word courses per language: Core (1,000 words), Pareto 1 (1,000 words), and Pareto 2 (1,000 words). Every pack includes native text-to-speech audio, real example sentences, usage notes, and structured reference lessons. Spanish — Core, Pareto 1, Pareto 2German — Pareto 1, Pareto 2 (Core included free)Esperanto — Pareto 1, Pareto 2 (Core included free)Italian — Core, Pareto 1, Pareto 2 (rolling out April–May)The Roots Series — (DLC)Four root systems that explain the shape of English and its European neighbours. Useful whether you're learning a foreign language or sharpening your native one — every Romance word you learn in Italian or Spanish connects back to a Latin root; every Germanic word in German mirrors an English cousin.German Roots — the Germanic backbone of everyday EnglishNorman Roots — the second vocabulary, 1066 and afterLatin Roots — constructing words from their parts - May 8thGreek Roots — prefixes, stems, and suffixes - TBAIncluded Free with the Base GameFlashBoss ships with three full 1,000-word packs at no extra cost:German Core — 1,000 words, ready for A2 immersion classEsperanto Core — 1,000 words, will get you very farEnglish Adept — 1,000 words of carefully selected EnglishEvery card includes a definition or translation, example sentences, and optional usage notes. All presented with high quality Piper text-to-speech audio. Choose Your MasterSix masters, six teaching styles, six session limits — from Luna's gentle pacing to Odiin's stoic warrior-poet discipline. Ranges from 8 to 34 cards a day, roughly 5 to 30 minutes.🐺 Luna — gentle and encouraging, 8 cards per day⚫ Claude — analytical and precise, 13 cards per day🐉 Shen — stern and direct, 13 cards per day🦉Odiin — master and founder, 21 cards per day🦊 Kitsune — playful trickster, 34 cards per day🦅 Aquila — noble and disciplined, 34 cards per dayWhy Terminal?Lightweight. Distraction-free. Runs on anything. Language learning shouldn't need a gaming rig. FlashBoss also has caching built in — open the in-game help menu to learn more.SetupWindows 10+ (Windows Terminal recommended for emoji support)macOS 10.15+ / Ubuntu 20.04+Numberpad recommended, but not required