WhatsApp is not directly made available to Kindle, but this does not mean you are not able to download it and use it.
In order to obtain it and use the application, you need to follow through with these instructions. If you do not, you are either not going to find the application, or it is not going to work on your device.
First, you need to download WhatsApp onto your current mobile phone. A number must be associated with your WhatsApp account, but since your Kindle doesn’t have a number, you need to associate one to it. However, you cannot associate your current mobile phone’s number to it since WhatsApp is specific to one device. So, you need to purchase a new SUM card with a number associated with it. You can purchase a SIM card that is a pay as you go, and since you are not actually going to be using any minutes on it, you don’t need to purchase any minutes. The SIM card itself should cost only a few dollars at most.
Remove the SIM phone from your current mobile device and pop this one in. Now, launch the WhatsApp application on your mobile phone (which you can download from the App store you use). Now, launch the application and when you access the contacts, select to save the contacts with the SIM card.
Now, open up the Internet browser on your Kindle and head over to the WhatsApp website. Select the “WhatsApp.apk” download link. You might find your current Internet browser in the Kindle does not reach the necessary page for this. If this is the case, download Google Chrome from the App Store on your Kindle, then go to the WhatsApp website and select to use the Desktop Site. The .apk is the Android download link, which is what you want (if you still have trouble with this you can download it on your computer, then email the file to yourself to open on the Kindle).
Select the .apk downloaded file on the Kindle and follow the instructions on the WhatsApp installation page. You are going to be asked to associate a phone number with the application. To do this, you want to type in the SIM card number of the new SIM card you purchased then submit it. Once WhatsApp identifies it as a real, working number, it is going to allow you to use the application on your Kindle