Sneak preview of whatsapp messages I asked this question before , but without proper solution. 
I'll try to describe it better maybe someone will guide me the right way. 

Let's say you started a conversation in whatsapp with your friend and you're also a member in a few groups. While you are waiting for your friend to reply you opened your email app or your favorite news app , etc. Some members of one of your groups have started to flood your Whatsapp with messages (but you don't want to silent the group). You are still waiting for your friend to answer. 

The situation is that while I'm doing something in another app, I can never know if my friend reply without stopping from what I'm doing right now(reading, watching , playing...) and open Whatsapp to check it. Most of the times it is just messages from the groups or someone that maybe I don't want to reply right now.

I think that it is very basic feature that iOS have, why android doesn't have something like that ? 

P.S. - I tried NILS app which is the closest app I could find, but it doesn't do a great job.
I remember you asking about this before ;)  All you can do is - disable pop up for group notifications and enable pop up for individual members. Remember that iOS notifications are totally different from Android's.