One of the apps DESTROYING Windows Phone reputation is...
Seriously, I don't understand why Microsoft don't do anything to resolve the situation with this app. It's a disaster. It doesn't work properly, notifications don't appear, messages don't appear... Look at the Store comments for more info.
Is that hard for MS to invest some money to help WhatsApp devs to improve the service for Windows Phone?
In all the markets where WhatsApp usage is high, its performance is bad enough to choose another OS. And sure people will never look again to another WP device after that terrible experience.
Microsoft, do something.