You will create an application that utilizes the Vonage Voice API to make outgoing text-to-speech phone calls using Java. To complete this, you need a Vonage API account, a virtual phone number, and JDK 11 installed. You'll use Gradle to manage dependencies and run your application. The application will initiate a phone call using the Vonage Java Client Library and execute a text-to-speech message using Nexmo Call Control Objects. To test your application, you need to start it with the `gradle run` command inside the project directory.