OK. I'm coming back with this.
I didn't know much about WhatsApp. So to clarify some things.
From what I understand:
1. WhatsApp in iOS for example, loads your contact list inside the App. People who use WhatsApp have a little status underneath their name, so you know they have the App.
This does not happen in this webOS App.
What you can do is press on a contact and open a chat window. There you can see the contact's timestamp. "Last seen on Tuesday" etc.
With this you know that the guy uses WhatsApp. However, there is an option where people can hide their Timestamps. If they have enabled it, you don't know that they indeed use the App. That's the "problem".
2. It seems that in other OSes, like iOS, we are automatically added to our friend's contact list with the message. "Hey there! I'm using WhatsApp" which is the default message. So there is no problem to that. People WILL know that we use WhatsApp if they check their contacts.
3. When someone is inside our chat window we can see "Online" and "Typing". This cannot be hidden like the Timestamp. However, because we have the dashboard thing, when other people look at our chat window they will always see us online, even if we are not using the app at the time (minimized).
4. For me the problem is that if I talk with a friend for example and just for a moment I turn off the screen, I will not get the message before 15' or unless I turn on the screen again manually. If this could be fixed the app would be very good.
I hope I was clear as I tried to explain all these things. I may be probably be wrong in something, if it is true please correct me.