Version Control Made Easy – GitHub For Windows & Mac
GitHub is one of the most popular hosted version control services around and, besides its premium plans, usage is completely free for open source projects.
Many widely-used projects are hosted there (including Node.js Ruby on Rails, PHP or jQuery) and it definitely helps taking the code under control + improving the code with the contribution of others.
If you are like me; "work better with GUI apps rather than the command-line" and use GitHub, they now have free-to-use desktop apps for popular operating systems.
Both applications offer almost all the functionality that can be reached from command line tools and ease the usage for developers like me : ).