Applications can individually be allowed or denied access to your WiFi and/or mobile connection.
Blocking access to the internet can help:
- reduce your data usage
- save your battery
- increase your privacy
- No root required
- Simple to use
- Free of charge
- Open source
- No extra battery usage
- No calling home
- No tracking or analytics
- No ads
- IPv4/IPv6 TCP/UDP supported
- Block system and user applications
NetGuard does not even require the internet permission.
NetGuard is possibly the first free and open source no-root firewall for Android.
Most of these features are the result of sending selected traffic to a sinkhole, instead of filtering all internet traffic.
This means that advanced features, like address based filtering (needed for hosts blocking), traffic logging, and on-demand configuration, are not possible.
For up to date info on device compatibility, questions and answers please read more here: http://forum.xda-developers.com/showthread.php?t=3233012