SourceTree - Mac and Windows client for Mercurial and Git.
Gitea - A painless self-hosted Git service
GitKraken - The intuitive, fast, and beautiful cross-platform Git client.
GitLab - Create, review and deploy code together with GitLab open source git repo management software | GitLab
TortoiseGit - TortoiseGit is an easy to use client for the Git distributed revision control system.
GitBucket - GitBucket is the easily installable open-source GitHub clone written with Scala.