What is gitSQL?

gitSQL is a *free front end GUI for scripting out SQL objects into Flat File for use with Source Control such as GIT.

What does it do exactly?

Under the hood; gitSQL discovers database objects and then scripts them out using native database code. The schema is scripted out as create statements so that a database can be built directly from source control.

Does it script out Data too?

Yes - it does. Data can be scripted out into static data files. These files can then be imported into a database.