I cannot reproduce the problem, Walt.  It works fine for me.  In Feeddler, I added a dozen items to Safari's Reading List over a period of an hour, while Synkmark was actively syncing.  They all appeared in Safari on my iPad immediately, and they appeared in Safari on my Mac after 0-15 minutes.   This is typical iCloud behavior.  After they appeared on my Mac, Synkmark would perform a sync operation, import the new items to itself, but not export any changes because there was nothing to change.

I'll send you a refund if you want, but if you want to pursue further, please activate Synkmark and click the tab: Reports > Syncing.  You'll see a selection of Sync Logs, each one detailing an Import or Export operation.  In the pane below, it shows what items, if any Synkmark added, deleted (-) or changed (+).  Do you see your new Reading List items ever being deleted?

In the screenshot below, you'll see the list of my Sync Logs during my test.  The "Export" items are always followed by all zeros, indicating that no changes were ever made to Safari.  The "Import" items sometimes have some nonzero "+" values, indicating that items were added, and a couple times, to make more room on the screen and reduce confusion, I deleted some Reading List items in Safari on my iPad, and those "-" deletions were imported into Synkmark, as expected.

Another alternative: You could send me this data, and your entire configuration by activating Synkmark and clicking in the menu: Help > Trouble Zipper.  That might provide additional clues.

I still don't have any content in Feeddler

Update....

I turned off all syncing in Synmark on my Mac.  Now the "Add to reading list" works properly.  I'm wondering if Synmark is over-writing the reading list with blank content.

Thanks for the speedy reply.

Yes, that's the "Feedler" I am using.  Here's a screen shot.  If you long-press on a hyperlink, the menu appears. 
The same thing happens in Twitterrific, as seen in the second screen shot.  Both failed after I installed Synmark on my mac and connected Safari, Chrome and Firefox to it.

I'm running iOS8 on the iPad and OS X 10.10.4 on the Mac.

I really like the sorting and duplicate detection, as well as having all 3 browsers in sync, but I use the "Add to Reading List" feature so much that I would rather remove Synmark if it can't be fixed 

Walt

I usually create "Reading List" entries from my iPad using my RSS reader (Feedler) or from Twitteriffic, using their long-tap menus on a URL.  Since installing Synmark this feature has not worked.  I can get there by choosing "Open in Safari" from the long-tap menu, and then adding the page to the reading list from within Safari, but that's cumbersome and wastes a lot of time.

I noticed that in Synmark, these "Reading List" entries are appearing under "Unsorted Bookmarks".

Am I doing anything wrong?  If I can't use the "Add to Reading List" feature directly from these two apps, I would like a refund for Synmark.

Walt