How to add parent indicators (arrows) on primary menu

Website URL: http://www.tinderprofile.com If you look at the primary navigation menu at the top and hover over the 'Photo's and 'Resources' menu items, it displays sub menu items underneath. The user will not know these exist unless they hover on the menu items. How can I add simple arrows (parent indicators) on the 'Photos' and 'Resources' menu items so the user knows straight away there are sub-menu items here. I was able to do this on the free full frame theme but have lost the arrows after upgrading to full frame pro! The plugin I originally used ("Dropdown Menu Widget") to achieve this doesn't seem to be working with the pro version. HELP!