Files were not visible for a sourceforge issue, I think, now are available again.
Patterns support doesn't exclude the previous use of DropIt by file formats and is configured to create this association by default.
In fact if you drop an unknown file on it, a message allow you to add a pattern association. Click Yes and a window is opened to add the association, with automatically set "as example" the pattern to associate the file extension: *.txt
So if you want to use it with file format associations, you only need to use the default pattern when you drag and drop a file on it. If instead you want to use a more complex pattern syntax, you can click Rules
to see pattern instructions (you can find here examples of patterns supported).
Given that DropIt is designed to work also with the "old mode" of formats association, I prefer to keep available the software only from this first open source release 0.6.1 that is stable and complete (older versions could include issues).
Try now to use it.. I never used patterns before too, but it is simple and I decided to keep formats association as default to make software use fast.