BT Call Responder

An Android app that automatically sends an SMS reply when you miss a phone call.

When the auto-responder is enabled, BT Call Responder detects missed calls, sends your configured message to the caller, and keeps a history of every reply attempt. You can set a per-number cooldown so the same caller is not texted again within a chosen window (15 minutes to 24 hours).

Features

• Auto-reply — Turn the responder on or off and edit the message sent to missed callers.
• Cooldown — Optionally limit how often the same number receives a reply.
• Reply history — Review sent, failed, and skipped replies with timestamps and reasons.
• Reliability — Missed-call detection runs in the background via WorkManager, with optional battery-optimization exemption for more consistent delivery.

Requirements

• A device with telephony and SMS capability (the app installs on non-telephony devices but cannot send replies there).
• Runtime permissions: phone state, call log, and SMS.
• Targets the latest stable Android SDK (API 37 / Android 17).

Building

From the project root:

./gradlew assembleDebug
./gradlew testDebugUnitTest
./gradlew defaultDeviceDebugAndroidTest

Architecture

The project is a multi-module Kotlin app using Jetpack Compose (Material 3), Hilt, Room, DataStore, and WorkManager. Missed-call handling is log-authoritative: caller numbers come from the system call log, not from broadcast extras.

License

MIT — see LICENSE.