Zendesk - Zendesk is a beautiful, lightweight help-desk solution.
SourceTree - Mac and Windows client for Mercurial and Git.
Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community
GitKraken - The intuitive, fast, and beautiful cross-platform Git client.
HelpScout - Help Scout is a simple, straightforward way to provide excellent support
GitHub Desktop - GitHub Desktop is a seamless way to contribute to projects on GitHub and GitHub Enterprise.