APU ZAP is a free Android application developed by Serebias Rodrigues Gonçalves in the Utilities & Tools category. This app provides a simple solution for users who want to make calls on WhatsApp without saving the phone number in their contact list. With APU ZAP, users can directly enter the phone number they want to call and the app will automatically open WhatsApp with the number entered in the chat window.

The app has a user-friendly interface and is easy to use. It does not require any registration or login process. Users can simply download and install the app to start using it. With APU ZAP, users can save time and avoid cluttering their contact list with unnecessary numbers. However, it is worth noting that the app does not provide any additional features beyond its main function of calling on WhatsApp without saving phone numbers.