One of the Apps that I like the most is WhatsApp Messenger. I use it a lot with friends and also to communicate with my family in Uruguay. It replaces text messaging and it is free. As long as the other user has it installed in his or her phone it is totally free no matter where they are. I love it. WhatsApp uses the phone numbers from your phone’s address book to prevent spam messages. So the users know who they’re talking to via the chat, is not some random person but is actually someone from my contact list. WhatsApp also looks up phone numbers in the users’ address book with the intention to check which of those numbers are actually verified in WhatsApp to avoid any spam. Although users don’t remain anonymous because their names and phone numbers show up when using the app, I know who I’m chatting with because they are actually contacts from my own address book and not some random person like it has happened more than once in Skype.