Great for time tracking, works the best with Chrome extension plus Android app.
I didn't use all the features available but for my needs it worked out perfectly. Their customer service is very responsive and polite when it comes to inquiries made.
With the TrackingTime Extension for Chrome, Firefox, Safari, and Edge enhance Redmine with time tracking. Get automatic timesheets and enjoy TrackingTime’s in-depth analytics.
Redmine is a flexible project management web application. Written using Ruby on Rails framework, it is cross-platform and cross-database. It integrates with a number of different SCM:s including Subversion and Git. It has multi language support and can be extended with the help of plugins. Redmine is licensed under GNU GPL.
http://www.redmine.org/