Merge pull request #69 from unixorn/master

Break GUI clients out into separate section

README.md

@@ -56,6 +56,7 @@ For clarity's sake all examples in this document use a customized bash prompt in
   - [Books](#books)
   - [Tutorials](#tutorials)
   - [Scripts & Tools](#scripts-&-tools)
+  - [GUI Clients](#gui-clients)
 
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
 
@@ -662,7 +663,10 @@ After commiting, change the author of the previous commit. To do this, see how t
 ## Scripts & Tools
 
 * [firstaidgit.io](http://firstaidgit.io/) A searchable selection of the most frequently asked Git questions
-* [git-cola](https://git-cola.github.io/) - another git client for Windows and OS X
 * [git-extra-commands](https://github.com/unixorn/git-extra-commands) - a collection of useful extra git scripts
+
+## GUI Clients
+* [git-cola](https://git-cola.github.io/) - another git client for Windows and OS X
 * [gitx-dev](https://rowanj.github.io/gitx/) - another graphical git client for OS X
 * [Source Tree](https://www.sourcetreeapp.com/) - a free graphical git client for Windows and OS X
+* [Tower](http://www.git-tower.com/) - graphical git client for OS X (paid)