GitHub - Originally founded as a project to simplify sharing code, GitHub has grown into an application used by over a million people to store over two million code repositories, making GitHub the largest code host in the world.

Commit Together by Github - Now add co-authors to your commits

GitLab - Create, review and deploy code together with GitLab open source git repo management software | GitLab

GitKraken Glo Boards - Easily track tasks and issues from inside popular dev tools

BitBucket - Bitbucket is a free code hosting site for Mercurial and Git. Manage your development with a hosted wiki, issue tracker and source code.

Refined GitHub - Browser extension that makes GitHub cleaner & more powerful