You can prevent notification sounds and vibrations sounding, and prevent the screen from being locked automatically.

It supports not only the default dialer but also other dialers such as LINE, Skype and so on.

So please try out to see if it's available for dialers that you always use.

* This app prevents notification sounds and vibrations sounding by setting to silent mode during a call.

* Even in silent mode, important notifications such as alarms may sound.

* Please find items such as [Silent Mode] and [Do Not Disturb] from sound settings of your device and confirm what may sound before using this app.