Have you considered changing your menu markup so the parent buttons aren’t linked? You could repeat the parent button/link as the first item in a sub-menu. More info + ‘sticky hover’ fix here: https://css-tricks.com/forums/topic/hover-ios-vs-android/
I’ve come across a script called “DoubleTapToGo” that does something like JeroenR mentioned. That might offer a drop-in solution, but I’d personally opt for a menu restructure.