Tomcat Administrator is an adminnstrative application that ships with Tomcat. If you navigate to http://localhost:8080 while Tomcat is running, you can login to the administrator using the link on the top left hand side. Note that you need to add the following user to your <tomcat dir>\conf\tomcat-users.xml file in order to have access to the Administrator app and you Manager app (for security reasons they ship them disabled outof the box:)
<user username="admin" password="admin" roles="admin,manager"/>
If you have any more questions please consult the Tomcat docs, I think I’ve given you enough to head off in the right direction atleast.