Since it seems nobody could figure this out, I thought Id let you all know how the app works. And it does work.
You have to open the .doc file you wish to convert FIRST! Open it in safari, iBooks, Dropbox, whatever. Once youre viewing the file, hit the button in the top right of your screen that says "Open in..." And choose doc2pdf. Then hit convert. The app will be busy for around one minute, after which it will automatically take you to a safari page hosting your new pdf file. Again, tap "open in..." And choose an app.
One foreseeable downside is that iBooks doesnt offer a way to rename a file (that I know of), and the file name this app assigns will be just a jumble of letters. However, it is easy to rename files before saving when using Dropbox.
I just used this app to convert 10+ files to use them with Notability and it works great. Happy converting!
Bilbilface about Document to PDF