WhatsApp works on Android devices running Android 2.1 or later if the phone is able to receive SMS messages and calls. The app is not supported on tablets running the Android operating system or Wi-Fi only devices, as of 2015.
Android devices running WhatsApp will need to have a data plan if that device will be used other than on a Wi-Fi network.
WhatsApp is a cross-platform app that allows the exchange of texts, picture messages and voice messages. It runs off a user's data plan. Users can send unlimited video and audio messages and create group chat sessions.