Whatsapp has created a huge impact over the instant messaging world. It also holds the top spot, earlier owned by BBM, among all apps providing instant messaging service. With almost infallible service this app never fails to deliver. However, some users aren’t still completely satisfied with the service. Some complain about it’s “last seen” feature being a boon to stalkers. While others complain about it having a very basic look and feel.(If you want to customize Whatsapp you can check out Whatsapp+ ) A few feel it lacks the free SMS service.