As written on the SourceForge start page, voc-get is A "flash card"-like vocabulary learning program with a comfortable handling of several translations and score management.
The answer is on the Technique Page which gives you an overview and tells you why to use voc-get.
There is a package manager called apt-get for Debian. voc-get is a kind of package manager too: It "Download[s] some vocabulary from your keyboard and install[s] it in your brain."
The releases are usually on the SourceForge page, but there are not any releases uploaded yet. It is also possible to check out the CVS tree which you can also access by the SF page.
Read TODO and the ToDo explanation to find out what to do. The Hacking Conventions may also help you.
My native language is German and I have been learning English for about five years. Please contact me if you have discovered anything incorrect.