A couple tweaks that you can activate, like choosing a solid status bar, dimming wallpaper, dimming icons, choosing black navigation bars, choosing a transparent dock, etc. WinterBoard is basically a helper app to use with some free or paid themes. When you want to use a theme, you may be able to selectively choose only parts of the theme. For example, in the paid theme Auros, you can choose to display either the white icons or the black icons. In some cases, if you do not have WinterBoard installed and you purchase a theme on Cydia, WinterBoard will be downloaded in addition to the theme.