There is no doubt in it that whatsapp is a best messaging app which made everything so easy for people and as now they also provided free calling function , which is really great . you dont need to pay any more for calling and it is also not consuming so much data .
It is available in all android and other phones and it can run smoothly on all conections even 2G. This app provides everything like, you may share videos and audio clips , images text messages . I think after face book , whatsapp is a best messanger .