Skype is an application through which you can make audio and videos calls. Skype work on the base of VoIP . Its works peer to peer . If the other person have Skype installed in it phone than you can chat and can do video chat . Skype also allow VoIP services in the lowest rates on home landline number or mobile number . The rates are depend on the region . You can check the rete list for Skype calls on Skype.com . It is not limited for android but available for multi platforms. The new Skype layout is very smooth and flat through user can easily navigate.
Click here to download: http://goo.gl/FH8261
Tango is a very popular application in Google Playstore. This app also has a very cool option for free audio and video calls. Millions of account have been registered in Tango . You can also do regular chatting through Tango. This app is also available in multi platforms. As an additional features you can send different animations while chatting . Game can also me played in this application ,you can compete with your friends by challenging them in games.
Click here to download: http://goo.gl/MO52gI
Viber is also an application through which you can make free calls . It is also a VoIP service. Above than 200 millions people are connected with Viber network. The application has very easy and flat UI . All you need to install and register your mobile number and after that it will automaticity sync your phone contacts . The application works great with Wi-Fi , 3g or 4g LTE networks. As an additional feature recently Viber had also announced video call feature. Viber out is also available if you want to make outer calls than you can do it in very affordable rates . Check the rates on Viber.com.
Click here to download: http://goo.gl/hs5WhG
Facebook is a strong social media network . Recently Facebook announced audio call feature in Facebook messenger application. The messenger app is available for both Android and IOS. Facebook messenger is easy to installable on your device. It will sync your phone contacts and notify you about friends those are using messenger . For audio call you have High speed Wi-Fi network or 3g,4g or LTE . But you could make your call to messenger to messenger.
Click here to download: http://goo.gl/fDJCS9
Another very popular apps I would like to add is NImbuzz . Through Nimbuzz you can also make free calls all over the world . It is also a VoIP service. Calling quality is very fanatic in Nimbuzz . You can also make cheap international calls. Rate list available on the official website. The app works best on 3G , 4G networks . Other than calls you can make different groups with your friends and have fun with them.
Click here to download: http://goo.gl/g9uyC2