Building an On-Device AI Scam Detector for Android — Gemma 4 + LiteRT

Originally published on rohitraj.tech

UPI fraud hit ₹805 cr in India last year. Cloud APIs leak data. So I built ScamRakshak — fully on-device scam detection.

3-tier inference engine:

1. Gemma 4 LLM — context-aware classification
2. LiteRT — fast pattern model
3. Regex fallback — when battery low

Full architecture write-up: https://rohitraj.tech/en/notes/build-on-device-ai-scam-detector-android-gemma

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Read the full version with code samples and diagrams: https://rohitraj.tech/en/notes/build-on-device-ai-scam-detector-android-gemma