SPECIAL MENTION: An estimated 48 billion robocalls were placed to U.S. phones last year—a 57 percent increase over the year prior. Firewall was created to stop these calls from ever reaching you. For $3.99 a month, the app intercepts all calls from unknown numbers, sends them to a voicemail of your choice, and transcribes them for you to read. —Tara Law
Buy now: Firewall