WhatsApp Messenger is the world's most popular instant messaging app for smartphones.
You can use it to send and receive text and voice messages, photos, videos, even call your friends in other countries, and because it uses your phone's internet connection it might not cost you anything at all (depending on whether you'll pay data charges).
It's easy to set up and use. There's no need to create and remember new account names or pins because it works with your phone number, and uses your regular address book to find and connect you with friends who use WhatsApp already.
You can talk one-to-one or in group chats, and because you're always logged in there's no way to miss messages. Even if your phone is turned off, WhatsApp will save your messages and display them as soon as you're back online.
There's plenty more (location sharing, contact exchange, message broadcasting) and the app is free for a year, currently $0.99/ year afterwards.
What's New in Version 2.17.11
• You can once again set a text-only update in your profile and it's called About. Tap Settings and then your profile name to edit it. Thanks for the feedback!
• Play videos right away without waiting for them to download first. Videos will still be downloaded to your phone as the video is playing.
• Tap the new moon icon in the WhatsApp camera to better capture photos and videos when it's dark
• When editing a photo, 3D touch the crop icon to instantly crop the photo and fill your phone's screen