# Flashcards.world App Guide — On-Device Neural MOSS Voices, Local M2M-100 Translation & Offline Cloud Sync > Deep technical guide to Flashcards.world's on-device AI and offline-first architecture: downloadable HD Neural MOSS TTS voices, local M2M-100 multilingual neural translation, local SQLite storage across Web/iOS/Android, and conflict-free cloud sync. - **Canonical URL:** https://flashcards.world/flashcards/sets/bd812db1-77ab-4a3e-a5f4-17023f2b9760/ - **Markdown URL:** https://flashcards.world/flashcards/sets/bd812db1-77ab-4a3e-a5f4-17023f2b9760.md - **Level:** advanced - **Languages:** en → en - **Total Cards:** 32 ## Flashcards (32 Cards) | # | Front (Term / Prompt) | Back (Definition / Answer) | Example | Multiple-Choice Options | | :--- | :--- | :--- | :--- | :--- | | 1 | How can you check whether all your offline reviews have finished syncing to the cloud before closing your laptop? | Check the **Sync Status Indicator** in the top navigation bar: a green checkmark (`✓ Synced`) confirms all local SQLite deltas are safely backed up, while a spinning or offline badge shows pending local changes. | | | | 2 | What happens if you edit a card's text offline on Device A while reviewing the same card offline on Device B? | Card content metadata (front/back text, tags, mnemonics) uses Last-Write-Wins (LWW) per field timestamp, while FSRS-6 scheduling state (`stability`, `difficulty`, `lapses`) is merged via the review log stream—so your text edit and your review rating are BOTH preserved! | | | | 3 | What are the 'Downloadable HD Neural MOSS Voices' in Flashcards.world? | High-definition, on-device neural Text-to-Speech (TTS) voice models that you can download inside Flashcards.world to generate natural, human-like pronunciation offline without relying on robotic OS voices or cloud APIs. | | | | 4 | What should you do before boarding a long international flight to ensure 100% offline capability? | 1. Open your active decks once while on Wi-Fi (so all cards and images cache in local SQLite); 2. Verify your target language's **HD MOSS Voice** and **M2M-100 model** show `Downloaded` in Offline Settings; 3. Study seamlessly in Airplane Mode. | | | | 5 | Why is studying in Dark Mode at low screen brightness in the evening beneficial for memory consolidation? | Bright blue-spectrum light suppresses pineal melatonin secretion and delays Slow-Wave Sleep onset; Dark Mode preserves normal circadian melatonin rise so your brain enters hippocampal sharp-wave ripple replay on schedule. | | | | 6 | How do the 3 Track 9 Pillar Guides work together as a complete learning system on Flashcards.world? | 1. **FSRS-6 Guide** teaches the mathematical science of *when* to review; 2. **How to Study with Flashcards Guide** teaches the cognitive rules of *how* to formulate atomic cards and use the Feynman technique; 3. **Flashcards.world App Guide** shows *how* to execute every workflow across all 11 modes and offline tools. | | | | 7 | How does Keyboard Accessibility & Screen Reader support work in Flashcards.world? | Every study mode supports full keyboard navigation (`Tab`, `Space`, `1–4`, `Enter`, `Esc`), ARIA labels on interactive cards, and high-contrast visual diffs so learners can study hands-on without mouse strain. | | | | 8 | Why are downloadable on-device Neural MOSS Voices superior to standard browser/OS `window.speechSynthesis` voices? | 1. **Consistent studio-grade prosody and pronunciation** across all devices; 2. **Zero network latency** (instant playback on card flip); 3. **100% offline reliability** (works in Airplane Mode where cloud TTS voices fail or downgrade to robotic voices). | | | | 9 | How does Flashcards.world automatically choose which TTS voice to use for the Front vs. the Back of a bilingual card? | Each deck (and card) stores `front_lng` and `back_lng` ISO language codes (e.g., `front_lng: "ja"`, `back_lng: "en"`); when you flip from Front to Back, the audio engine automatically switches from the Japanese neural voice to the English neural voice! | | | | 10 | What is Flashcards.world's 'Offline-First Local SQLite Architecture'? | Instead of treating the mobile or web app as a thin wrapper that breaks whenever Wi-Fi drops, Flashcards.world stores your entire flashcard database, FSRS-6 state vectors, and review logs in a local **SQLite database** right on your device. | | | | 11 | What is 'Append-Only Review Log Sync' and why does it prevent data loss when you study offline on two devices? | Every flashcard review is saved as an immutable timestamped event `(card_id, rating, review_timestamp, duration_ms)`. If you study offline on your phone and tablet, the sync engine merges both event streams chronologically and recomputes the exact FSRS-6 state `(D, S)` without losing a single review! | | | | 12 | What are the 3 huge advantages of running M2M-100 locally on your device inside Flashcards.world? | 1. **100% Offline Translation**: translate words and sentences on flights, trains, or abroad with zero data roaming; 2. **Zero API Cost / Unlimited Usage**: translate whole decks without token quotas; 3. **100% Privacy**: your private study notes never leave your device. | | | | 13 | How does Dark Mode / High-Contrast Theme support in Flashcards.world protect your eyes during evening study? | Flashcards.world supports system-adaptive and manual **Dark Mode** across the app, card editor, LaTeX equations, and SVG diagrams—reducing blue-light exposure before sleep. | | | | 14 | How does the TTS engine handle Cloze syntax (`[answer\|hint]`) and LaTeX math (`$...$`) when reading a card aloud? | Before synthesizing speech, the text normalizer strips markdown syntax, reads only the unmasked prompt (on the Front) or the full completed sentence with the target answer filled in (on the Back), and converts math symbols into spoken words. | | | | 15 | How does Flashcards.world implement local SQLite storage across all 3 platforms (iOS, Android, and Web)? | On **iOS and Android**, it uses native embedded SQLite + local file-system media storage; on **Web / PWA**, it uses local IndexedDB / WebAssembly SQLite with Service Worker asset caching so even browser tabs work offline. | | | | 16 | How does Flashcards.world handle media file syncing (images, occlusion masks, custom `🎤` voice clips) across devices? | Media files are hashed by content (SHA-256), uploaded/downloaded asynchronously in the background, and cached locally on disk so media never blocks fast card-text and review-log synchronization. | | | | 17 | Can you install Flashcards.world as an offline-capable Progressive Web App (PWA) on macOS, Windows, Linux, or Chromebook? | Yes—clicking 'Install App' in Chrome, Edge, or Safari installs Flashcards.world as a standalone desktop app with full offline caching and local database persistence. | | | | 18 | How does 'Deep Linking' work between a Flashcards.world Study Guide and the iOS/Android/Web app? | Clicking any **Study Deck →** or module link in a study guide opens that exact 32-card set directly inside the Flashcards.world interactive study view, pre-loaded and ready for FSRS-6 practice. | | | | 19 | How can you translate an entire 32-card flashcard set into your native language using Flashcards.world? | Open the deck, select **Translate Deck**, choose whether to translate the Front, the Back, or add a bilingual subtitle line, select the target language, and run the batch translator. | | | | 20 | How do deterministic UUIDv4 Set IDs and Topic IDs work in Flashcards.world's PostgreSQL & SQLite architecture? | Curated sets and topics use deterministic SHA-256-derived UUIDs (`deterministic_set_id` and `deterministic_topic_id`) so every study guide URL (`/flashcards/sets//`), API endpoint, and local database record maps to the exact same immutable identifier worldwide. | | | | 21 | Can you use Flashcards.world completely anonymously / locally first, and link a cloud account later? | Yes! Every card and review you create in local guest mode is stored in your on-device SQLite database; when you sign in or create an account later, the app automatically migrates and syncs your local decks into your cloud account. | | | | 22 | Explain how FSRS-6 deterministic replay resolves a sync conflict if Card X was reviewed offline on your phone at 09:00 and on your tablet at 14:00. | When both devices sync, their review log events are sorted by UTC timestamp (`09:00` then `14:00`) and replayed through the deterministic FSRS-6 equations, producing the exact same final Stability ($S$) and Difficulty ($D$) on every device. | | | | 23 | What makes the 'M2M-100' architecture different from legacy English-centric translation models? | Unlike older models that had to translate `Spanish → English → Japanese` (pivoting through English and losing nuance), M2M-100 is a true **Many-to-Many** model trained to translate directly between any pair of 100 languages without an English pivot. | | | | 24 | How does the 'Cross-Device Cloud Delta-Sync Engine' keep your iPhone, Android tablet, and laptop synchronized? | Whenever a device is online (or comes back online after offline study), the sync engine uploads only the compact **delta changes** (new/edited cards and append-only FSRS-6 review log events) and pulls remote deltas since your last sync cursor. | | | | 25 | How do you download and manage Neural MOSS Voices on iOS, Android, or Desktop in Flashcards.world? | Open **Settings → Audio & Neural Voices (TTS)**, browse available language voice packs, tap **Download** next to your target languages, and set your preferred voice and default speaking rate (`0.5x` to `2.0x`). | | | | 26 | Why does storing flashcards in a local on-device SQLite database produce '0ms Flip & Grade Latency'? | Because every card read, FSRS-6 calculation, and rating write happens in local memory/disk in less than 1 millisecond—never waiting on a round-trip HTTP request to a remote server between cards! | | | | 27 | How do you download and enable the Local M2M-100 Translation model in Flashcards.world? | Go to **Settings → Offline AI & Translation Models**, download the quantized M2M-100 model package once over Wi-Fi, and toggle **'Use On-Device Offline Translation'** for instant local translation in the Card Editor and Deck Translator. | | | | 28 | Summarize the 5 technical pillars that make Flashcards.world the complete modern spaced repetition platform. | 1. **Native FSRS-6 21-Parameter Scheduler**; 2. **11 Multi-Modal Study Modes & Games** (including Feynman Grader & Handwriting Coach); 3. **AI PDF/Notes Deck Generator & Anki `.apkg` Importer**; 4. **On-Device Neural MOSS Voices & Local M2M-100 Translation**; 5. **Offline-First Local SQLite + Conflict-Free Cloud Sync**. | | | | 29 | How does Flashcards.world protect your privacy when using on-device AI models (MOSS TTS and M2M-100)? | Because inference runs locally inside your device's sandboxed memory using local model weights, zero audio recordings or card text are transmitted to third-party servers during offline TTS or translation. | | | | 30 | Why do all Flashcards.world Study Guide URLs and Set URLs enforce normalized trailing slashes (`/guides/en//` and `/flashcards/sets//`)? | To guarantee canonical URL consistency across static SEO study guides, sitemap indexes, and the SPA/mobile deep-link router without redirect chains. | | | | 31 | How much storage space do local SQLite flashcard decks typically require on a smartphone? | Text and FSRS-6 metadata are tiny—**10,000 flashcards take less than 5–8 MB** of SQLite storage, meaning you can carry your entire university degree or medical school curriculum offline in less space than two photos. | | | | 32 | What is the 'Local M2M-100 On-Device Neural Translation' model built into Flashcards.world? | A compact, quantized version of Meta AI's **Many-to-Many 100 (M2M-100)** multilingual sequence-to-sequence transformer model that runs directly on your device to translate flashcards between 100+ language pairs completely offline. | | | --- Study this deck interactively with FSRS-6 spaced repetition, audio review, and multiple-choice mode at [Flashcards World](https://flashcards.world/flashcards/sets/bd812db1-77ab-4a3e-a5f4-17023f2b9760/).