Private WhatsApp Chat description

Private Whatsapp Chat is an where you can open an unknown number with WhatsApp without saving it to your contacts

This app uses WhatsApp public API to open a chat with any number you enter (a chat between you and that number, it is NOT possible to spy other conversations).
No contact is created on the device, so you don't need to save the number on your contacts list in order to open the chat. Simply open the app, enter the number, click the button and the chat will open (if the number exists, otherwise Whatsapp will notify it).