Go to Settings > About Phone > System Updates to see if a newer version of Android (like 5.0+) is available for your specific device.
Just to clarify: is a standard messaging app available on the Google Play Store. There is no official or safe version of WhatsApp called "444 lifestyle and entertainment." Downloading modified or unofficial versions (like WhatsApp Plus, GB WhatsApp, or similarly named variants) can pose serious risks:
Como o suporte oficial acabou, mesmo instalando o arquivo, o servidor do WhatsApp pode impedir a verificação do seu número de telefone. Passo a passo para instalação via APK: