Every FlashBoss pack is built from two things: a word list and a set of reference lessons. Available here — free to read, free to print, or to use as you like without restriction.
FlashBoss is the structured learning system that combines them: Fibonacci-derived spaced repetition for adaptive study sessions, a choice of master guides and difficulty, boss fights, audio, and a structured, distraction-free learning environment.
Word lists
Every word in every pack, laid out by tier and cluster — target word and translation, nothing in the way. Hide the translations to quiz yourself, or print a cluster and cut your own flashcards.
Open the word directory →Lessons
The reference lessons that fire inside FlashBoss — pronunciation, grammar, usage — rendered exactly as they appear in the terminal. Organised by language and tier, each one unlocking what you're about to read. Tap any line to hear it.
Open the lessons →Reference sheets
One-page references built to print and pin up. More arrive as each pack ships.
Esperanto correlative table (PDF) →FAQ
How do I start? As a beginner, just start — tier 1 builds everything from the ground up. Already know some of the language? Take the Tier Skip Challenge: a placement test in BossRun format, three chances per attempt. Pass it and you skip the tier.
Interface stuck in the wrong language? Ctrl+L opens the language menu from almost anywhere in the program — English, German, Spanish, Japanese, Simplified Chinese, Russian.