Is there a good free Android app that actually blocks telemarketing calls?

Call Blocker is a straightforward and effective solution for Android users inundated with telemarketing calls. The app's primary function is to automatically intercept and block calls from numbers not in a user's contact list, a feature that directly addresses the core issue of unsolicited sales calls. For users receiving dozens of unwanted calls daily, this 'whitelist-only' mode can significantly reduce interruptions. Reviews indicate this is where the app excels, with multiple users stating it succeeded where other paid alternatives failed.

The app operates by using a community-powered blacklist and allowing manual number blocking. A key feature for telemarketing scenarios is the automated blocking of hidden or private numbers, a common tactic for some call centers. The interface is simple, focusing on core blocking functions without complex settings. This simplicity, however, comes with trade-offs. Some users report occasional performance issues, such as the app hanging during launch, which can be a minor frustration. Furthermore, while the ad-supported model keeps it free, the whitelist approach is a blunt instrument; any call from a non-contact, including legitimate but unexpected calls like from a doctor's office or delivery service, will be blocked and sent to voicemail. This necessitates occasionally checking missed calls. For individuals seeking a zero-cost, aggressive defense against relentless telemarketers, these imperfections are often considered a worthwhile trade-off for the peace and quiet provided.