Make Okular notes visible in acrobat
Solution 1:
The annotations done in Okular are stored in the ~/.kde/share/apps/okular/docdata
folder.
There should be a .xml file for each annotated pdf.
In the future, you may want to use PDF X-Change viewer of Foxit Reader for Windows through Wine. These sava annotations in the pdf itself and are visible in Adobe Reader or any other pdf reader for that matter.
Solution 2:
There doesn't seem to be any way to do so within Okular, but you can save Okular annotations back into pdf format with Xournal by "printing to a file":
Solution 3:
The more recent releases of Okular save the annotations directly into the PDF.
For example, on Ubuntu, if you go to the Ubuntu Software Center and install Okular, then it should work fine out of the box.
(for more details, see here)
Solution 4:
I'm using Okular 0.19.3 on Linux Mint 17.1.
I added lots on annotations, then quit. Open again with Okular, notes are there, good. Open with Adobe Reader, NO notes visible :(
Opened again with Okular, did print to a pdf file. Opened output file of print function with Adobe Reader, notes are visible, Yea :)
Will they be there on android and Mac pdf file viewers? Yes, on both platforms.
I don't have a Windows system readily available to confirm but likely yes there also.
paul