Call Insider vs Callfilter.app

Call Insider is a free caller-identification service available on Android and the web. It helps people assess unknown phone numbers by showing ratings during calls or in a pop-up. The mobile app uses a database with more than 300 million identified numbers, drawing data from more than 100 websites. A downloadable database covering more than 100 countries supports lookups without an internet connection. Users can rate numbers, read other users’ ratings, see yearly interest in a number, and sometimes view a landline location. The service is intended for calls such as telemarketing, surveys, courier contacts, and office calls. Free registration provides fewer ads, editable rating history, reply notifications, more daily comments, and easier reporting of harmful comments. Call blocking for potentially harmful and unsaved numbers is described as in development. The service was created in the Czech Republic in 2011.

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.