LeviRinger Android App

LeviRinger is an open-source Android app for people who need to hear calls from selected contacts even when their phone is silent. The user keeps a local VIP list and chooses when an incoming call should start an alarm-style alert. The app works on the device.

The problem

Silent mode and Do Not Disturb can hide a call that matters. Raising every call would defeat those settings. LeviRinger applies the exception only to enabled contacts and only when the schedule and device state allow it. It leaves the carrier call in place while showing an alert for the matching caller.

Key features

• A call-screening service receives the incoming number without rejecting the call.
• The VIP list stores names, numbers, notes, enabled state, alert tone, vibration choice, and contact time windows.
• Call decisions and VIP contact records stay on the phone; no server or account is involved.
• A global schedule supports selected weekdays and windows that cross midnight.
• Rules skip alerts when the phone already rings normally, unless the user enables that option.
• A foreground service plays audio with Android's alarm usage and can vibrate or boost alarm volume.
• An optional full-screen caller card can appear over the lock screen when Android permits it.
• Onboarding guides the user through the permissions and call-screening role needed for operation.
• English and Arabic resources are included for the app interface.

Technical architecture

The Android call-screening service hands a candidate number to an alarm controller. The controller reads VIP entries from SQLite and settings from SharedPreferences, then applies the rule evaluator. If the caller qualifies, a foreground service manages delayed playback, vibration, the notification, and cleanup when the call ends or the alert is stopped. Number matching handles local and international forms. All decisions happen on the handset.

Engineering highlights

• Time-window logic treats the after-midnight part of an overnight schedule as belonging to the previous selected day.
• A pure rule evaluator makes contact, schedule, ringer, and call-state decisions testable without an Android service.
• Alert playback uses the alarm audio category and releases resources when the alert stops.
• Debug builds use a separate application ID, so they can coexist with a release install.