Case Study

Mobile

Enter t u r n

O is a Flutter mobile app built around one minimal ritual. The user presses and holds a central circle, called the "O", to enter a daily "Return": a short authored Line followed by a choice. The whole experience is drawn with custom GLSL shaders and ambient sound so it feels calm and quiet. The app signs users in through the XXXIII web platform using secure OAuth.

Flutter

GetX

REST API Integration

Challenges & solutions

The technical problems our team solved to ship a reliable, unified digital experience.

The animated MIRA background and ring dropped frames on older phones.

Moved the rendering into GLSL fragment shaders and precomputed text textures, so the work runs on the GPU.

If the OS killed the app while the user was signing in in the browser, the callback was lost.

Handled both the initial link and the live link stream with App Links, and kept PKCE state in secure storage so sign-in resumes correctly.

Choices made without a network connection were lost and the user saw errors.

Built an optimistic UI that enters the void immediately, stores submissions in a local queue, and syncs them once the connection returns.

The cached Return could be outdated when the app was reopened.

Added a staleness check before using the cache, with a fallback to a fresh fetch from the server.

Users who started anonymously could lose their progress after signing in.

Linked the anonymous participant ID to the account during the OAuth handoff, so progress carries over.

Key features

What users get in the finished, shipped product.

Press-and-Hold "O" Interaction :

Interaction : Initiates each experience through an intuitive press-and-hold gesture.
Animation : Features animated ring progress to provide visual feedback during interaction.
Transition : Creates an immersive transition into the void scene.

Daily Returns (TURN Engine) :

Delivery : Presents authored lines sequentially, delivering one Return at a time.
Selection : Supports current-turn fetching, position tracking, and option selection.
Limits : Enforces daily Return limits to manage the experience.

Shader-Driven Visual Scene (MIRA) :

Rendering : Powers atmospheric visual experiences through GPU-based rendering.
Shaders : Features custom GLSL backgrounds and interactive ring shader effects.
Animation : Integrates text textures and tweened scene transitions for a fluid visual experience.

Secure Sign-In via XXXIII :

Authentication : Connects account access between the web platform and the mobile application.
Security : Implements OAuth 2.0 with PKCE for secure authentication.
Integration : Supports system-browser sign-in and deep-link callback handling.

Anonymous Participant Mode :

Accessibility : Allows users to begin their experience without creating an account.
Identity : Automatically generates an anonymous participant profile.
Upgrade : Enables users to upgrade to a full account at a later stage.

Offline Support and Optimistic Submission :

Availability : Keeps the experience functional even without an active network connection.
Caching : Stores turn data locally for offline access.
Synchronization : Queues submissions offline and automatically syncs them when connectivity is restored.

Ambient Audio Experience :

Atmosphere : Creates an immersive environment through continuous ambient background sounds.
Playback : Supports looping ambient audio for an uninterrupted experience.
Lifecycle : Manages audio playback according to the application's lifecycle state.

Secure Local Storage :

Protection : Safeguards authentication tokens and user data on the device.
Encryption : Uses encrypted storage for sensitive authentication information.
Sessions : Supports persistent sessions and secure logout functionality.

Account and Data Management :

Data Access : Allows users to view their anonymous participant data.
User Control : Provides self-service account deletion functionality.
Compliance : Supports user data management requirements aligned with App Store policies.

Reliability and Error Handling :

Networking : Implements a centralized API client for consistent network communication.
Exceptions : Uses typed exceptions to handle different error scenarios reliably.
Logging : Provides request logging to support debugging and troubleshooting.
User Experience : Displays clear and user-friendly error dialogs when issues occur.

Tech integrations

Third-party SDKs & libraries

5 core integrations powered

XXXIII Web Identity Platform

Core system integration

Deep Linking

Core system integration

Flutter Secure Storage

Core system integration

Audioplayers

Playback engine

Quick Actions

Core system integration

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Enter t u r n

Flutter

GetX

REST API Integration