Direct Zapp

Direct Zapp helps you send your messages through the WhatsApp® application without having to have your mobile number in your contacts.
You just have to select the country, enter the DDD and number you want to send the message to in Direct Zapp and click the WhatsApp® icon next to it when it lights up, which means the number format you entered is correct and validated. WhatsaApp®.
For the app to work you need to have WhatsApp® installed and properly configured on your smartphone.