NetGuard provides simple and advanced ways to block access to the internet - no root required.

Applications and addresses can individually be allowed or denied access to your Wi-Fi and/or mobile connection.

Blocking access to the internet can help:
• reduce your data usage
• save your battery
• increase your privacy

Features:
• Simple to use
• No root required
• 100% open source
• No calling home
• No tracking or analytics
• Actively developed and supported
• Android 4.0 and later supported
• IPv4/IPv6 TCP/UDP supported
• Tethering supported
• Multiple device users supported
• Optionally allow when screen on
• Optionally block when roaming
• Optionally block system applications
• Optionally notify when an application accesses the internet
• Optionally record network usage per application per address
• Material design theme with light and dark theme

PRO features:
• Log all outgoing traffic; search and filter access attempts; export PCAP files to analyze traffic
• Allow/block individual addresses per application
• New application notifications; configure NetGuard directly from the notification
• Display network speed graph in a status bar notification
• Select from five additional themes in both light and dark version

There is no other no-root firewall offering all these features.

VirusTotal: https://www.virustotal.com/gui/file/8866a39b0b5c1092cd744adbc7db2bb4ae774ddd2bb1a2556b1b03591b57c749