Whatsapp is probably the most popular mobile app and I too like it a lot but I m certainly not happy with the set of emoticon they provide with the app. there are plenty of useless emogies which people almost never use like those few chinese characters and those black and white weird looking objects. I m not saying those things should not be included but they could have separate them with other ones.
Like they could have made them optional to download as a separate package. coz when I try to find a particular emoticon it takes me a lot of time to find coz I have to search among all those. plus unlike facebook or hike they dont provide any facility to add customized emoticons we r compelled to use only that much. so it could have been my favorite mobile messenger app but due to that one problem I dont lilke it a lot