Back in April, I declared using 3D Touch on the App Store icon to quickly update all apps was the most amazing use of 3D Touch ever. And it was! Until a few days ago when I accidentally discovered what I now consider the best use of Apple's pressure-sensitive screen.
I suspect most people hide or categorize apps using folders. It's helpful for decluttering your home screen, but it's super-annoying to tap multiple times to view which apps have notifications awaiting your attention. The process usually goes like this: You open the folder, and if the app with the notification isn't on the first page you have to swipe to find it, then open it and repeat the process.
But if you own an iPhone 6S ($450 at Sprint) or iPhone 7, use 3D Touch to press on the folder icon and you will find a list of which apps have notifications, and better yet, tapping on the app will launch the proper app. It's a super-useful shortcut that's hidden, just like almost all of of 3D Touch's shortcuts are.