All major IDE's (Visual Studio, Eclipse, Netbeans, Qt Creator etc) offers a "switch between header and implementation functionality". On use, IDE will open a file inside a project that has a same name as currently viewed but complimentary extension. For example, if i'm editing "wnd_main.m", editor will open "wnd_main.h", if any. And if i'm editing "wnd_main.h" editor will open "wnd_main.m" (.mm/.c/.cpp whatever found). Compared to "go to declaration" in AppCode this allows to jump header / source file without selecting any methods first.
Does appcode have this functionality in some form? I have searched hotkeys and menu items but didn't find anything that resembles it :(