A free program for Android, by splaish.
This is the best way to get an idea of how the incoming call screen will look like.
It allows you to have a look at how the caller ID will be displayed on the screen.
In addition, you can try out the different themes that are available.
If you want to have a look at the themes that are available, you can go to the menu.
It also allows you to set a caller ID so you can be notified when a call is coming in.