Stock Alert is a lightweight, opinionated alerting tool for serious investors, built around a single goal: capture your price triggers reliably without forcing you to watch the screen. ARCHITECTURE - Quote source: public Sina Finance endpoint covering A-shares (SH/SZ), Hong Kong and US - Trigger model: percent threshold (up / down / both) computed against previous close - Cooldown: per-rule cooldown in seconds to suppress flapping - Time windows: trading hours only / custom range / all day, auto-aligned to each market's session - Background polling: BGAppRefreshTask + BGProcessingTask schedule continued monitoring while the app is closed - Notification model: UNNotificationSound + timeSensitive interruption level, ringing up to 30s on the lock screen - Foreground fallback: switches to AVAudioSession playback so the silent switch can't swallow critical alerts DATA HANDLING - All data persisted locally via SwiftData β watchlists, rules, history - No accounts, no server, no third-party analytics - Uninstall removes everything; no iCloud residue DELIVERY METRICS - Ready to use on launch, single binary under 5 MB - Only two permissions requested: Notifications and Background Modes - Requires iOS 17.0+, built on SwiftData and modern SwiftUI TYPICAL WORKFLOW 1. Add tickers: type sh600519 / 00700 / aapl β market is auto-detected 2. Configure rules: pick the stock, percent, direction, window and cooldown 3. Wait: the system schedules background fetches; on hit, push + alarm fire 4. Review: every trigger appears in the History tab for post-mortem No sign-up. No subscription. Install and run.