Built from my curriculum spec: Paul Nation’s four strands (input, output, language study, fluency at about 25% each), a 96-unit spiral of ten YKI themes across four six-month phases, and a weekly loop (listen → shadow → grammar → write → speak → re-listen → check + mission).
Sentences are the atom. Every word’s dictionary form and analysis comes from the Voikko morphology analyzer, not from a language model, and a unit is only published when its words are at least 95% known or planned vocabulary. No server and no sign-in: progress, cards and recordings stay in your browser. Audio uses your device’s Finnish voice, so it sounds best in Safari or on Android.