Silent Block

Tiny Android app that silently rejects incoming calls. No ringing, no missed-call notification — calls are dropped before the dialer reacts.

Features

• Master switch — one toggle to block every incoming call across all SIMs.
• Per-SIM rules — independent mode for each SIM:
  • Off — let calls ring normally.
  • Unknown — block calls from numbers not in your Contacts.
  • All — block every call to this SIM.
• Uses Android's CallScreeningService (API 29+) — clean, modern, no reflection.

Install

Download the APK from the latest release and install it on your phone (enable Install unknown apps for your browser/file manager).

After install:

1. Open Silent Block.
2. Tap Set as screener → grant the Call Screening role.
3. Tap Grant permissions → Contacts + Phone.
4. Adjust per-SIM rules as desired.

Build from source

JAVA_HOME=/path/to/jdk17 ./gradlew :app:assembleDebug
# APK at app/build/outputs/apk/debug/app-debug.apk

Requires Android SDK 34, build-tools 34.0.0, JDK 17. Min device: Android 10 (API 29).