The Crossword App | Daily Crossword Unlimited

Social Layer

A Built In Social Network

Unlike most crossword apps, this product ships with a fully functional social environment, driving retention through competition and connection.

Real Time Messaging
Full in app chat backed by Firestore. Includes content moderation: message flagging, user blocking, and a profanity filter that prevents inappropriate text from being sent.
Friend Code System
A streamlined 6 character alphanumeric code protocol. Users share their code to connect with friends, no phone number or email required.
Dual Leaderboards
Global rankings and private Friends Only leaderboards. Both are live queries against Firestore, no manual curation required.
Referral Reward Loop
Invite a friend sharing generates a unique deep link. When the invitee signs up, the referrer is automatically credited with free puzzle unlocks.

Authentication

Four Identity Providers

Multi platform sign in with no dependency on a single ecosystem. Built for maximum distribution across Android, Fire OS, Samsung, and iOS.

Google Sign In

Primary provider for Android and Google Play. OAuth 2.0 with hashed stable user IDs.

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Apple Sign In

Required for iOS App Store compliance. Native integration via Sign in with Apple SDK.

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Amazon Sign In

Tailored for Amazon Fire OS and the Appstore audience. Login with Amazon integration.

Samsung Sign In

Targets Samsung Galaxy Store distribution. Samsung Account integration.

All providers are architected as an independent auth layer, no Firebase Auth dependency. User IDs are deterministically hashed and stored in Firestore for cross device persistence.

Monetisation

Three Revenue Channels, Live

A hybrid free to play and subscription model, designed so every type of user generates revenue.

Google AdMob
Rewarded video integration for Google Play. Users watch a rewarded ad to unlock additional puzzle slots beyond the free daily limit. Test mode auto activates in debug builds to protect account standing.
Unity Ads
Rewarded video integration specifically for Amazon Fire OS devices, where AdMob has no coverage. Seamless SDK swap based on platform detection at runtime.
In App Purchase (Premium Subscription)
Quarterly subscription plan via Flutter's in_app_purchase SDK. Grants unlimited ad free play. A fully built paywall screen includes purchase, restore, and Terms of Service flows.

Core Engine

Custom Built Game Engine

Every component of the crossword experience was built from scratch, no third party game libraries or off the shelf engines.

Custom QWERTY Keyboard
Built entirely in Flutter, bypasses the unreliable native soft keyboard entirely. Provides 100% accurate, fast letter entry with auto advance between cells and direction toggling.
Intelligent Clue Navigation
Linked Across/Down tab system synced with grid selection. Tapping a clue jumps to the correct cell. Animated tab transitions prevent state mismatches.
Archive with Completion Tracking
Two tab archive: Available and Completed. Progress and completion timestamps are persisted locally, replay a completed puzzle from exactly where you left off.
Live Content Sync via Pull to Refresh
Puzzles are delivered dynamically from Google Cloud Storage. A pull to refresh action invalidates the cache and fetches newly published puzzles, no app update required to add content.