Learning should be habitual, not optional. By embedding a vocabulary quiz into the daily alarm routine, retention becomes automatic—users don’t choose to study, they study because the alarm won’t stop until they answer correctly. A 3-stage backup chain ensures the quiz can’t be bypassed by force-quitting. New users often abandoned the app when their word list was empty; a short AI-driven placement quiz after signup fills that gap with five level-matched starter words so the app feels usable from minute one. Combined with AI-powered content generation via Gemini and spaced repetition, every morning starts with meaningful practice. This entire app was built 100% by AI—from architecture decisions to every line of shipping code, using Claude Opus 4.6 as the engineering team.

After sign-up, new users pick the language they want to study and the app’s main interface language, then complete a five-question vocabulary placement quiz. Each item is AI-generated; difficulty ramps up after correct answers and steps down after mistakes so the session stays challenging without punishing early errors. Results determine five starter words that Gemini recommends at an appropriate level—those cards land in the user’s library immediately so the deck is never empty on first launch. From there, set alarms with time and repeat days. When an alarm fires, a 30-second word quiz appears—letters reveal progressively, and the user must type the correct answer to dismiss. If the quiz isn’t solved, backup alarms fire at 5, 3, and 2 minute intervals. Between alarms, browse flashcards organized by groups, study by swiping cards (right for Know, left for Don’t Know), or use AI Smart Scan to photograph a textbook page and extract vocabulary automatically. Gemini generates definitions in the background. The spaced repetition engine surfaces cards at optimal intervals based on mastery level—6 levels with intervals from 1 to 30 days. Track progress through stats with 7-day charts and mastery distribution.

Flutter handles the cross-platform UI with Provider for state management. Alarms use the native alarm package for reliable background scheduling on iOS 13+ and Android—audio plays even when the app is killed or locked. A 3-stage backup chain (5 → 3 → 2 minutes) persisted to SharedPreferences ensures the quiz can’t be bypassed by force-quitting. Flashcards, groups, and quiz results live in Firestore with unlimited cache enabled for offline-first operation—pending quiz results queue locally (up to 100) and sync when connectivity returns. All AI features—definitions, Smart Scan, word categorization, onboarding placement questions, and starter-word selection—run client-side via the firebase_ai SDK connecting directly to Gemini 3 Flash with no Cloud Functions in the stack, eliminating server costs and cold starts. Spaced repetition uses a custom SM-2-style algorithm with 6 mastery levels and fixed intervals (1, 2, 4, 7, 14, 30 days). Home screen widgets use SwiftUI on iOS and Kotlin on Android, reading shared data through app group UserDefaults and SharedPreferences.