How can I allow internet access for foreground apps while blocking background apps on Android?
Sometimes you may want the foreground app to use the internet for a minute or so while blocking background apps to save data and protect privacy. But Android doesn’t differentiate between foreground and background apps for network access as long as the apps are running (see Why do apps run in background on Android?). There's a solution.
Fyrypt is a firewall app which lets you temporarily unblock foreground apps, ensuring that only the apps you are actively using can access the internet.
How's the magic? You can configure how long the app stays unblocked after you stop using it. Plus you can unblock related apps as groups.
Related: