Build your own Anki.

# Build an original app inspired by Anki

You are an experienced mobile product designer and mobile engineer. Build a working, polished MVP from the brief below. Implement the core journeys end to end; a static mockup is not sufficient. Inspect the current environment, make sensible implementation decisions, and get started. Ask a question only if a missing answer genuinely blocks implementation.

Starting platform: iOS. Explicit customized Product & audience and Tech stack requirements take precedence over this starting target.

## Product & audience
Build an original native iOS flashcard app called Recallbox, inspired by Anki’s deck and recall-review workflow. It is for learners creating their own simple question/answer cards and studying a due queue. The primary journey is adding a deck, reviewing the front, revealing the answer, rating recall, and returning when the scheduler makes the card due. Deliver a working SwiftUI/Xcode project with an explicit scheduling algorithm rather than unexplained due dates.

## Design
Use an original compact deck list, readable card editor, and distraction-free review screen. Keep reveal and recall rating separate so someone cannot grade a hidden answer accidentally. Show the next interval before confirming a rating. Support VoiceOver, Dynamic Type, high contrast, native keyboard navigation where supported, and reduced motion without relying on a flipping animation.

## Features
1. Deck authoring: create and rename decks, add plain-text front/back cards and optional tags, search cards, and archive/suspend a card. Provide original starter examples separately from user decks. Validate empty sides and confirm deletion of decks with cards.

2. Review queue: select due cards using stable ordering and a daily new-card cap, reveal the back, and allow Again/Hard/Good/Easy ratings. Commit each rating once, display remaining due counts, and let the learner stop and resume a session.

3. Scheduler: implement a small documented spaced-review algorithm with learning steps, intervals, and a lapse rule. Use an established appropriately licensed library only if verified, or clearly label the simpler original schedule. Do not claim Anki scheduler/file compatibility.

4. History and undo: persist review events and prior scheduling state, show a calendar of actual reviews, and undo the latest rating by restoring its before-state. Editing a card’s wording must not silently erase its review history.

5. Offline backup: create, edit, and study entirely offline. Import/export a bounded app-owned JSON or CSV through native file pickers and sharing with field mapping, preview, duplicate-ID handling, and a clear report of skipped invalid cards.

## Tech stack
Use Swift, SwiftUI, SwiftData/Core Data, and testable Swift scheduler/date modules for a new native project. Include Xcode configuration, simulator run instructions, deterministic scheduler fixtures, and a versioned local schema. Render card text safely rather than arbitrary HTML or scripts. Native file selection should use scoped access and handle cancellation/denial. Retain a compatible native repository when available, but do not replace the app with a website or WebView. No AnkiWeb account or network service is required.

## Data & behavior
Deck {id, name, dailyNewLimit}; Card {id, deckId, front, back, tags, suspended, createdAt}; ScheduleState {cardId, stage, dueAt, intervalDays, repetitionCount, lapseCount, version}; ReviewSession; ReviewEvent {id, sessionId, cardId, rating, reviewedAt, beforeState, afterState}; ImportManifest. Update a rating and its scheduling state atomically with an idempotent event ID. Distinguish exact timed learning steps from calendar-day intervals and document the selected study-day/time-zone policy.

Acceptance checks and scope:
Create three cards, rate one Again and one Good, advance a controlled test clock, and verify the due queue plus interval previews. Undo a rating, suspend a card, edit text, force-close mid-session, and restore a backup. Test duplicate submissions, midnight/time-zone boundaries, CSV quoting, invalid imports, and large text. Build/test the native app and disclose any unavailable device checks. Exclude .apkg parity, unrestricted HTML templates, copied decks, AnkiWeb synchronization, add-ons, advanced media, and claims that a simple scheduler equals Anki’s full implementation.

## Originality and assets
The named product is a reference for general workflows only. Use an original product name, visual identity, wording, layout, and assets. Do not copy proprietary code, branded logos, distinctive screens, private APIs, paid templates, or protected media. Use original or appropriately licensed sample data and assets. Build from this brief rather than scraping the reference service. Do not imply affiliation with the referenced company.

## Implementation quality
- Make every visible control work, with clear loading, success, empty, validation, and failure states. Remove controls for unimplemented features.
- Support the target platform and responsive or resizable layouts where appropriate. Use platform-appropriate accessibility semantics, labels, keyboard operation, visible focus, sufficient contrast, and reduced-motion preferences. Provide alternatives for drag-only interactions.
- Validate inputs at the relevant boundary. Treat imported or user-generated content as untrusted; render it safely. Confirm destructive actions or offer undo.
- Keep state changes reliable across navigation and reloads. Never silently lose edits. Handle persistence and network errors with an actionable message.
- Keep the scope realistic. Prioritize the complete primary journey. If a custom Features section differs from the baseline, update the data model, design, and acceptance checks to match it; explicit custom requirements take precedence over baseline assumptions.
- Provide realistic original sample content and a useful empty state. Keep sample data clearly separate from user-created data.

## Delivery and verification
1. Inspect the repository and outline the implementation in a few sentences.
2. Implement the app and connect its actual data flow. Continue until the primary journey works.
3. Run appropriate checks and test the acceptance cases above on the target platform. Verify responsive layouts and keyboard navigation when browser tools are available. For native projects, build with the available SDK and test an emulator or device when possible; report any missing native verification honestly. For games, verify the rules and gameplay loop, not only the menus.
4. Fix observed failures, then provide the runnable result, setup/run instructions, a brief explanation of what is implemented, and any specific configuration or verification limits.

This is a focused MVP. Do not add billing, AI services, or unrelated features unless explicitly requested in the brief. Start building now.