Like any other link building tool this tool can create backlinks to any URL in order to boost that URL rankings for its keywords.
So you can use this tool for main page/home page or deep pages/posts/categories or whatever.
I wrote that this tool is also for deep pages/posts, because I saw that people are only submitting their home page to the tool.
I have explained this many times before... but once more...
Building links only towards your home page is not natural and can be recognized as such and those backlinks can eventually be devaluated by google, which will then lead to lost rankings, etc...