Firewall - Spam Call Blocker is a full-version utility app developed by Ad Hoc Labs INC. It is specifically designed to block spam calls, fraud calls, and robocalls. Unlike other robocall blocker apps, Firewall works differently. Instead of trying to determine which numbers spammers use, Firewall only allows calls from people approved by you from your contact list. This feature ensures that you only receive calls from people you want to hear from.

Firewall also offers other features to help keep your number private and your productivity high. You can avoid unwanted text messages with their SMS spam blocker, screen messages with visual voicemail, and pause the blocker when expecting an important call from an unknown number. The app also lets you make anonymous outbound calls to unknown numbers, eliminating the risk of exposing your personal number. Firewall is built by Ad Hoc Labs, the same company that makes Burner, the award-winning 2nd phone number app.

Firewall is free to try for 14 days, and if you love it, you can continue with a subscription plan of $3.99/month. The app is only available for Verizon, T-Mobile, AT&T, and Sprint customers. Firewall has received rave reviews from Macworld, CNET, and Axios, among others.