iOS8 adds a new quick contacts feature to the app switcher (you know, the view when you double-press the Home button) but not everybody is thrilled with it. If you want to hide your frequent contacts from this view, you can do it easily in the settings.
In case you’re still not sure what we’re talking about, here’s a comparison of before and after changing the setting… on the left-hand side you’ll see the Favorite and Recent contacts on the top view, and on the right you’ll see that they are hidden the way it was in iOS7.
To toggle this preference, head into Settings -> Mail, Contacts, Calendars, and then Show in App Switcher.
Inside that panel you can toggle them on or off.