Dropbox feature is bunk – PDF Converter Pro. Review

For 3 dollars you'd think they would have worked the bugs out. But all I need is to access my Dropbox and convert the files there to PDF and then access the dropbox from another app. I have no idea where's my documents folder is on the iPad. And the when trying to access my Dropbox it only tells me that I am not "loged in" and yet gives me no option to do so.
Review by zhongshan on PDF Converter Pro..