Guardian Firewall VPN works by encrypting your data and in turn, keeps you out of harm’s way for free. This lifestyle app can serve as your mobile firewall as well. It also has a Tracker Alert feature that sends you reports of the third-party companies or organizations that have access to your personal data on the internet. You can use the report to monitor your own activity and tread more carefully to avoid apps mining your data without you knowing. This VPN can also detect malware and phishing to keep you guarded with security. It has a user-friendly interface even newbies can navigate. However, you may experience some issues with the connection speed with the app’s free version.