TimeCamp allows you to integrate with various different project management services. Instead of creating the project structure from scratch, you can import projects/clients/tasks lists from applications like Basecamp, Trello, Podio, Jira or many others. You can check the full list of available integrations here
You can also track time to those integrations with Google Chrome plugin, allowing you to use a timer directly on your favorite project management web page. This plugin is available for Asana, Trello, Podio, Teamwork and Insightly. You can install it from here.
For specific information on how to enable available integrations, please choose the one that interests you from list below:
Pivotal Tracker integration