<p>WhatsApp offers free text messages using your mobile number, and also offers free calling to other WhatsApp users. It is completely free and also offers voice and video chatting. Groups are also very common on WhatsApp. The reason for which WhatsApp tops this list is not because it is any better in the making itself, which it is not. It is because it is most popular and has more than a billion users. This increases your chance of communicating for free with people worldwide since communication is free and possible only between users of the same service. </p><p> Here is another tool that connects you to hundreds of millions of people worldwide. Its user base is in fact the huge social network that Facebook is, and the app allows you to communicate through texting and voice calling with these people. </p>Line offers a lot of features, more than WhatsApp and Viber. Besides the free messaging service, users can also call on another for free, for any length of time and from any location to any other location in the world. Line is also a newborn social network.Kik is developed by an enthusiastic team and is optimized for being a fast and robust app. It transforms regular texting into real time conversation. It works on different platforms and is support on most platforms including Symbian, which is quite rare in this list.<p>Viber works just like KakaoTalk, and has also a huge user base, nearing 200 million. It also offers free text messaging and free voice calls to other Viber users, and has group text messaging. It is available for the iPhone, Android phones, BlackBerry but not for Nokia and Symbian.</p>KakaoTalk is a Korea-based company that offers free text messaging along with phone calls. The messages and calls are free only to KakaoTalk users. It has a huge user base and you don’t need to register – it uses your mobile phone number. It allows group text messaging and some other features. It is available for most smartphone platforms.Jaxtr allows you to send text messages to other Jaxtr users for free. You can also send real SMS messages to other people that are not using Jaxtr, against payment. But the rate is much lower than the GSM rate. For instance, an SMS to a mobile phone in the US costs 1 cent. It is the only service in this list that allows texting to users outside its network. Jaxtr uses your phone number and is available for most mobile platforms.Text Plus works the same way as most of those mentioned in this list, but there is something to it that will interest you if you live in the US and Canada or call and text there regularly. Text messages and voice calls are free to other Text Plus users, and are also free to any other mobile phone (non-users) in the US and Canada. It does not support BlackBerry.Talkatone works just like Text Plus – free texting and free calls to all other Talkatone users and to any number in the US and Canada. It works on Wi-Fi, 3G and 4G. However, it is available only for iOS (iPhone, iPod and iPad) and Android.