Clone the repository: git clone git://github.com/toggl/toggl-button
Navigate to chrome://extensions/ and enable "Developer Mode".
Choose "Load unpacked extension..."
Open the src directory in the toggl-button directory you just cloned and follow the prompts to install.

Using the Button

Log in to your Toggl account and keep yourself logged in (no need to keep the tab open).
Go to your TeamWeek, Pivotal Tracker, Github, Asana, Unfuddle, Gitlab, Trello, Worksection, Redbooth, Podio, Basecamp, JIRA, Producteev, Bitbucket, Stifer, Google Docs, Redmine, YouTrack, CapsuleCRM, Xero, Zendesk, Any.do, Todoist, Trac, Wunderlist, Toodledo account and start your Toggl timer there.
To stop the current running timer:

press the button again
start another time entry inside your account.
go to Toggl to stop or edit your time entry.

Custom domains

If you use a setup, where one of the supported services is on a custom domain you can customize the extension to fit your needs. Here is a step by step guide on how to add custom domain to the extension.

Contributing

Want to contribute? Great! Just fork the project, make your changes and open a Pull Request

Don't know how to start? Just check out the user requested services that have not yet been implemented, pick one and start hacking.