This program was developed especially for software developers. With it, you are able to document all steps of the developing process. Especially with multiple programs and many versions, it makes an overview much easier.
Here, you enter all new features and reported bugs. While developing, you can read this information and implement it. Because of the integrated version control, you see always in which state the function or error is. And you see in which version the function was implemented, or the error was corrected.
There are similar systems for this task. But this application was optimized for very small teams. Without it, you have not the overview of all functions and error correction in all your applications.