PhoneBook is an Arabic caller ID and search engine application that allows users to identify unknown calls and stay protected from spam calls. The app has millions of records for countries like Saudi Arabia, United Arab Emirates, Kuwait, Bahrain, Oman, Qatar, Yemen, Jordan, Lebanon, Syria, Egypt, Iraq, Morocco, Tunisia, Algeria, Sudan, Palestine, Libya, Comoros, Djibouti, Mauritania, and Somalia.

The core functionality of the app is to display a popup window when an unknown incoming call arrives, helping users to search before deciding to answer or reject the call. Additionally, PhoneBook displays a list of incoming calls that do not exist in the contacts list, allowing users to search and identify them before deciding to add them to the contact list.

The app features a search box for mobile numbers, a list of unknown calls from the call log, a list of contacts, and a window caller popup when an unknown incoming call arrives. PhoneBook also displays a warning popup window if the incoming call number is in the block list or is a spammer. The app notifies the user if new names appear in the app for their number and removes abusive names.