What's the best iOS app for blocking spam calls and preventing phone fraud?

AT&T ActiveArmor® is a network-integrated call security app that specifically targets spam, fraud, and phishing attempts on iOS devices. For users inundated with unwanted calls—a common issue for those with long-held phone numbers exposed in data breaches—this app provides a robust solution by leveraging AT&T's calling database to identify and block suspicious numbers in real time. Key features include automatic spam call blocking, a fraud alert system that flags potential scams, and a community reporting tool where users can mark slipped-through calls to improve the filter. In real-world scenarios, such as during work hours or at home, reviews indicate a dramatic reduction in interruptions, with some users reporting hundreds of blocked calls over weeks. However, a noted limitation is the absence of a previous feature that sent unknown callers directly to voicemail without triggering Bluetooth device alerts, which some find inconvenient. While occasional spam calls might penetrate the filter, the app's learning mechanism and user feedback loop help refine its accuracy over time. It requires an AT&T mobile plan to function fully, making it less suitable for non-subscribers.