I agree with @Sara,  I have tried it once I did not like it, too much people talking, It is impossible to correct the mistakes. 

I'm not a part of any group conversation via Whatsapp/Skype/etc because I think it's not safe to give a random stranger your phone number or talk with them through video chat. There's a high posibility that a stranger would use your personal info and disturb you. I prefer sending messages via Italki and booking a professional lesson that's guaranteed to be helpful. Plus, those Whatsapp groups are not helpful if that's just some non-native speakers with low level of language knowledge talking to each other. They can teach each other wrong.  I think that there should be some groups, here on Italki, for chatting but with advisory of a native speaker. 

The main problem is not last for long only for temporary then died