Most apps like Google Hangout, Skype, and Zoom give you the option to make and receive calls by logging in to their site on your web browser without downloading any special software. “In digital security, we call this your ‘attack surface.’ Reducing that surface is always a good idea.” “Every time you install a new app on your device, you’re adding another back door into your system, with more potential software vulnerabilities that hackers can try to exploit,” says Cody Feng, project leader for security and privacy testing at Consumer Reports.