M'flat is an iOS 7 theme that is not in Cydia, but is still one of the nicest looking themes around. M'flat includes a variety of icons that look very nice and appear throughout the phone, even when sharing a file using the share button.
This iOS 7 theme is available as a download from this reddit thread. Users will need an app like iFile to download it, unzip it and then move the files to Library/Themes. From there it will show up as a standard Winterboard theme.
M'flat is free on Reddit