About WhatsApp Newest/Latest Version 2.12.360 Installation
WhatsApp .apk 2.12.360 is currently in BETA on whatsapp.com, it can’t be installed from the Play Store. However, but we can still install whatsapp v2.12.360 on your Android device. Note this v2.12.360 is not a stable version, it’s only for testing purpose. You can manually download and install it on your Android phones or tablets now.
To install an APK file that was downloaded outside Google Play Store, you will need to enable “Unknown Sources” and it can be enabled from either Settings->Security or Settings->Application. This depends on your Android OS version that runs on Android device.