For one reason or another, often we have to
block internet access to certain applications. Android's primary functions do not really allow such action to succeed, but with some firewall applications, you can do it easily.
Whether on your smartphone or your tablet, some applications may be consuming high data without you really have the ability to control them. In Android, there is a function of imitate downloading or sending data from some applications in the background. However, there is a difference between limit and block.
Also, it may happen that you do not want to receive messages or notifications from applications such as Whatsapp, Viber, Skype or Facebook Messenger. Rather than having to cut directly off your data connection or Wi-Fi connection, it is possible to restrict the incoming or outgoing connections to certain applications of your choice tightly. To do this, you just need the free application "NoRoot Firewall". There are other similar apps like Netguard or Mobilwal, but we will describe here the application "Firewall without root " which pretty well does this job.