WhatsApp is one of the most popular messaging apps on the planet. Here's how to add your iOS and Android contacts to your WhatsApp list to easily stay in touch.

You can add new contacts to WhatsApp manually from the Chats tab or you can scan someone's QR code within the app.

Want iPhone-style contact posters on your Android phone? The updated Phone app now comes with the Calling Cards feature. Here’s how to create them for your contacts.

You can create a contact list, called a group, in the Contacts app on an Android phone to send messages to. This can be useful if you frequently want to create a text message to the same group of ...