Call Defender is a free app that offers spam call blocking and caller identification features. By turning on the "Spam Database," users can enjoy a spam-free life without any additional charges. The app provides a real-time caller identification feature that displays the names of public or private organizations when they call. It can identify over 500 thousand Hong Kong phone numbers, including hospitals and educational institutions. The app's database is updated every 10 minutes to effectively eliminate spam calls.

Call Defender aims to provide a simple solution for blocking unwanted calls and protecting user privacy. It utilizes a comprehensive global database with over 700 million numbers to identify unknown calls. The app also offers advanced settings for customizing call blocking and provides a daily call report for any blocked or missed calls. Additionally, it features an Anti-fraud Information Center that educates users about fraud.

To ensure proper functionality, users are advised to load the app at least once after installation. The point-rewards system will be deprecated, and users using optimization software should designate Call Defender as a trusted app. A network connection is required for database download and the caller ID feature. Compatibility issues may arise for devices using unofficial Android frameworks.

The privacy policy for Call Defender is not provided in the given text.