Cheetah Track
Toggl is a time tracking tool that allows teams to easily allow its members to track time accross multiple projects. Check out more on www.Toggl.com .
Cheetah Track allows users to start, stop and view their Toggl timer straight from Slack. Instructions and demo at cheetah-track.herokuapp.com.
Cheetah Track is an unoffocial tool and is in no way associated with Toggl.
Big thanks to the Toggl folks for providing an easy to use, well documented and open api.
Also a big thanks to kanet77 for creating a ruby wrapper for aforementioned api.