Windows do have a WhatsApp App, but then its more of a web wrapper which is not that fluent when it comes to notification and misses the whole point of being an app on the platform, just like Amazon.
Now the news is coming in that Facebook, which owns WhatsApp, is finally testing a native desktop app in their beta program. If you are into the beta program, you may want to download the app and try it out. The App link is live, but then its, not the app you are looking for now.
While I expect it to be a UWP App, but what I am hearing is that it’s an electron app. It’s basically an open-source framework created by Cheng Zhao and now developed by GitHub. It allows for the development of desktop GUI applications using front and back-end components originally developed for web applications: Node.js runtime for the backend and Chromium for the frontend.
We will keep you posted when this goes live on the Windows Store.