Actually it would be dead simple for evernote to fix this. Ok, you can't pull in files from other apps - but you can easily go to the other app (eg PDF Expert) and "open in..." To evernote. Evernote receives the file fine, but it only allows you to create a new note, not add the file to an existing one. Basic software fix. The problem is Evernote - if hey enabled you to choose the note to add to - hey presto, problem solved. Please Evernote, ios has come along in leaps and bounds on terms of inter app operability, and you're lagging behind on this one. It would make such a huge difference to be able to bring in PDFs to existing documents - it's a big part of research. Easy fix - so why not?