CORE PHILOSOPHY
Kalkra is deliberately offline and single-player. It holds no accounts, makes no network calls, and ships with no telemetry, so “Data Not Collected” is a truthful answer on every storefront rather than an optimistic one. Progress is stored locally and signed; durability of a player's history was chosen over tamper-proofing it, because losing someone's training record is the worse failure.
SYSTEM ARCHITECTURE
Game UI (Flutter) ↓ providers Game Engine (Adaptive Calibration) ↓ services Local Persistence (signed, on-device)
KEY CAPABILITIES
• Adaptive Engine: Real-time difficulty adjustment based on solving speed.
• Fully Offline: No accounts, no network, no analytics — nothing leaves the device.
• Local Progress: Stats, streaks and history stored on-device and signed against accidental corruption.
• Cross-Platform: One Flutter codebase across macOS, iOS and Windows.