The Samsung Galaxy S6 and Galaxy S6 Edge hasn’t been released into markets yet and we already got all the S6 TouchWiz stock Apps and Wallpapers from the leaked system dump. The Apps included in the Galaxy S6 are all redesigned with fresh Material Design touch and includes some extra features.
Bear in mind that you have to have TouchWiz running on Android 5.0 Lollipop in order to install and run those stock app replacements if you do, then the road is clear. Here are the Download links.