Beekeeper Studio : Open Source cross-platform SQL Editor and Database Manager. Use Beekeeper Studio to query and manage your relational databases, like MySQL, Postgres, ...
Gitea : Gitea is a community managed fork of Gogs, lightweight code hosting solution written in Go and published under the MIT license.
Code Maat : Code Maat is a command line tool used to mine and analyze data from version-control systems (VCS).
Git Extensions is the only graphical user interface for Git that allows you control Git without using the commandline. It comes with a manual and video tutorials to get you started quickly.