To use YouTube Android Player API in your app, you have to register it and obtain API key. This post show you the steps to do so.
- Login with your Google account in Google APIs Console.
- Pull-down the Slection on left, and click Create... under Other Projects.
- Enter name of your project.
- Enable YouTube Data API v3 to ON.
- And then click to select API Access, and you will found you API key. You have to insert it in your code to use YouTube Android Player API.
To develop Android apps with YouTube Android Player API, read the posts in YouTube Android Player API step-by-step.