Add SmartGit alternatives

replace/smartgit.md

+---
+product: SmartGit
+type: git GUIs
+layout: replace
+---
+
+# SmartGit
+
+## GitAhead
+
+GitAhead is a graphical Git client for Windows, Linux and macOS. It features a fast native interface designed to help you understand and manage your source code history. 
+
+{% infobox %}
+  - **Website** gitahead.com
+  - **Source code**: [GitHub](https://github.com/gitahead/gitahead)
+  - **License**: [MIT](https://github.com/gitahead/gitahead/blob/master/LICENSE.md)
+{% endinfobox %}
+
+## git-cola
+
+Git Cola is a sleek and powerful graphical user interface for Git.
+Git Cola is free software and written in Python (v2 + v3).
+
+{% infobox %}
+  - **Website**: git-cola.github.io
+  - **Source code**: [GitHub](https://github.com/git-cola/git-cola)
+  - **License**: [GNU General Public License v2.0](https://github.com/git-cola/git-cola/blob/main/COPYING)
+{% endinfobox %}
+
+## gitg
+
+gitg is a graphical user interface for git. It aims at being a small, fast and convenient tool to visualize the history of git repositories. Besides visualization, gitg also provides several utilities to manage your repository and commit your work.
+
+{% infobox %}
+  - **Website**: [GNOME](https://wiki.gnome.org/Apps/Gitg)
+  - **Source code**: [GNOME](https://gitlab.gnome.org/GNOME/gitg)
+  - **License**: [GNU General Public License v2.0](https://gitlab.gnome.org/GNOME/gitg/-/blob/master/COPYING)
+{% endinfobox %}
+
+## ungit
+
+The easiest way to use git. On any platform. Anywhere. 
+
+{% infobox %}
+  - **Source code**: [GitHub](https://github.com/FredrikNoren/ungit)
+  - **License**: [MIT](https://github.com/FredrikNoren/ungit/blob/master/LICENSE.md)
+{% endinfobox %}