Found a solution today, and here is how it works:

1. Download gedit-plugins:

   
   
   

   sudo apt-get install gedit-plugins 
   
   




2. Go to Gedit preferences and enable the plugin. Restart Gedit.




3. Open a .tex file and open its .pdf output in Evince. The two files must be in the same folder.




4. Hold Ctrl and left click at any desired location in Evince. This will highlight the current row in Gedit.

Hope that helps!

Things I couldn't get working yet:

• Ctrl + left click in Gedit does focus the window of Evince, but does not highlight anything.

Things I haven't tested yet:

• Using Synctex with a document consisting of multiple files.