I remember in ios 8. You were able to go on setting>notification and then click on a app setting to set how many notification from the same app appear in your lock screen or notification center. For example I'm on a whatsapp group chat. So before on ios 8 I had it set to show only the 5 most recent messages in my LS or NC. Now with ios 9 they removed that option. So now when I'm away from my iPhone I have like 30 notification from the same app and sometimes I have to scroll to see if I have other messages from other apps such as messenger. Anybody else noticed this? Or is there a way that I don't know where I can set it back to 5 or 10 most recent?