Callfilter.app vs NumBuster

Callfilter.app is an Android app that blocks incoming calls according to rules set by the user. It can reject 8-digit numbers, numbers on a personal list, custom-pattern matches, or all incoming calls. Custom matching supports regular expressions, and users can choose to receive a notification when a call is rejected. CallFilter checks calls on the device through Android’s CallScreeningService API, using a local SQLite-based rule engine without remote database lookups. The maker describes it as offline, with no accounts or tracking. Its privacy policy says the app does not send personal data to external servers and does not use third-party SDKs, advertising networks, or tracking libraries. The app is free and open source, and the maker invites users to audit or contribute to the project on GitHub. It filters calls according to the user’s settings; it does not replace the phone app. The Play Store listing warns that some features may not work correctly on Samsung devices running Android 12 or later.

NumBuster identifies unknown callers and helps users screen phone fraud, spam, and unwanted messages. Its Android app can display caller information during a call and check numbers from the call log. The iPhone app also provides caller information on the call screen and call-log checks, and can block phone numbers. The homepage describes an anti-spam SMS client for Android, while a web app provides phone-number checks and help categories covering free and paid features.

Users can review and rate numbers, contributing community information that may help others assess potential threats. NumBuster says telephone-number information comes from registered users’ activity, not a purchased subscriber directory. A free mobile app is available alongside LIGHT, SMART, and PRO+ subscriptions, whose features vary. Depending on the tier, paid features include removing ads, page access blocking, AI reports, additional page cards, anonymous checks, visitor identification, and more monthly checks. The privacy policy describes safeguards including encryption, access controls, monitoring, backups, and vulnerability management. Non-users can submit privacy and deletion requests through supported website mechanisms without installing the app or creating an account. Feature availability can vary by country, operating system, app version, device, provider, platform capability, or legal circumstances. The terms say the service and mobile apps are not intended for residents of the EU, Bahrain, or the UAE.