The WhatsApp messaging application does not officially offer a desktop client. The good part is that they have WhatsApp Web available. Based on WhatsApp Web is also the unofficial WhatsApp linux application written in C ++ using gtkmm-3.0 and webkit2.
License - GPL-3.0
Last updated -19 June 2020
Snap Installation - Ubuntu 16.04+:
sudo snap install whatsapp-for-linux