I have ezPDF Reader on my Android tablet and this works well for editing pdfs within Evernote. My usual approach is that I view the note in Evernote that contains the pdf. I don't edit this note, but just click on the three dots beside the pdf. A dialog pops up asking whether I want to "Edit" or "View" and I choose Edit, and another asks if I want to use ezPDF or Skitch and I choose the former and do my editing. Then on closing it asks whether I want to replace the document and I choose replace, and everything stays the same but with a newly edited pdf. Overall it's pretty seamless and easy. It's fortunate that I fell into this mode by happenstance because I never would have used Evernote without this functionality. It's about 80% of my Evernote usage. (Now reading this thread, I'm worried that this functionality will disappear, but that's another matter.) I just assumed everyone was doing things this way, but came across this thread as I was trying to get another PDF editor to work this way. Although I've installed a few, ezPDF is the only one that works like this. I'd be interested to see if it works for other people too. If not, all I can say that may be unusual is that I had may have had ezPDF installed before Evernote was installed, whereas the others I installed after Evernote. Also, btw, this only works when Skitch is installed. If not, I just get a dialog to install Skitch.