The calling screen in android naugat version 7.1.1 is totally changed. that is why i have put it first on the top. check the new calling screen below, it is very neat and clean. simply simple.

android nougat version 7.1.1

Few app icons like  default Caller icon is also changed, check the screenshot below for few changes in icon.

android nougat version 7.1.1

android nougat version 7.1.1 android nougat version 7.1.1 android nougat version 7.1.1