NetGuard is a free application for devices running Android 5.0 or up that allows you to control which app may send or receive data.

It is difficult usually to find out what applications do on mobile devices as you are limited in terms of what you can run on the device to track usage.
While you can set up a monitoring solution to overcome this, most users probably don’t as it is not easy.
There are plenty of reasons why you may want to control the apps connecting to the Internet. Privacy comes to mind for example, as you can prevent apps from leaking data for example or block advertisement this way from being displayed in the app.
Other benefits include saving data by blocking applications from using it, and saving battery.
Applications like the excellent NoRoot Firewall help in this regard as they let you control Internet access.
NetGuard requires no-root access or even the Internet permission, which means that you can run it on any device running Android 5 or higher. The app is very simple to use, open source, and ships without advertisement or tracking, or phone home functionality.
The app requires that you set it up as a VPN connection to control Internet traffic and provide you with its functionality. This is done by enabling it after you have launched the application on your device and accepting the prompt that is displayed on first run.
Basically, it directs all app traffic through the VPN connection it controls and blocks connections this way giving you full control of an apps’ connectivity.
It displays a list of user-installed and system applications that you can control connectivity afterwards. All system apps are highlighted in orange for better distinction. Each app is listed with its name and toggles to enable or disable WiFi and mobile data.
You will notice right away that everything is disallowed by default which means that apps running on your phone may stop functioning if they require Internet.
To enable mobile data or WiFi for an app simply tap on the symbol next to it to do so. You may want to enable Internet for a web browser for example among other applications.
The settings provide you with additional options. You may use them to enable WiFi or mobile data by default for all applications for instance, reset all rules to start anew, or enable the dark theme to replace the default theme.
All in all though, it is a simple application that gives you full control over an application’s Internet connectivity.
The one downside is that you cannot use a VPN connection at the same time you are running NetGuard.

Download it by searching NetGuard no root firewall on google play store

Just put off your data
Daz all

AFWall+ has been doing that.

ivoatt:
Download it by searching NetGuard no root firewall on google play store

Will there be issues if one is using VPN to browse like psiphone or simple server.

AwesomeRomeo:
Will there be issues if one is using VPN to browse like psiphone or simple server.

It will off one for another