Try Out 3D Touch Apps
One of the best parts about 3D Touch on the iPhone 6s is that it works in third-party apps so you can use it in more than just the stock Apple apps on your iPhone 6s or iPhone 6s Plus.
If you want to try 3D Touch in a game, AG Drive is one of the first options available. It is $2.99 in the App Store with the use of a firm press to accelerate.
DropBox is a free app that allows users to preview files or folders with a firm press. You can also use a Quick Action from the home screen to get to recent files.