iKontacts for WhatsApp is a free Chrome extension that allows you to save all unknown WhatsApp numbers to your phone. The app will export all new WhatsApp numbers to a text file, which you can open on your computer. You can use this tool to save numbers into your phone contacts so that you don't have to remember the number you use for WhatsApp anymore.

When you open the app, it will start downloading the list of WhatsApp numbers. It will also allow you to import contacts from a computer and upload the file to online drives. This will allow you to see all new contacts and manage them all easily. You will be able to add all these numbers by opening the Contact menu and selecting Create New Contact. After saving all numbers, you will be able to open them in your contacts app and see the name of each one.