Marco learned a hard lesson about software lifecycles.
Even if you install the latest APK, the app performs a server-side check. When the server detects you are connecting from a device running Android 4.4.2, it will eventually block the connection for security reasons. You will see a message saying: "WhatsApp works with Android 5.0+ and above. Please update your device." whatsapp para android 4.4.2
Advertencia sobre Modificaciones y Apps Falsas (WhatsApp Plus) Marco learned a hard lesson about software lifecycles