On Samsung Galaxy S7 (Edge), you can pin a specific app/window on the screen, so others can just access that specific app/window. To pin apps on Galaxy S7 and Galaxy S7 Edge, you need to do as follows:
1. Open the Settings application
2. Scroll down to the Personal settings, and go to the Lock screen and security settings
3. Go to the Other security settings which is at the very bottom of the page
4. Scroll down to the Advanced option and touch the Pin Windows option
5. Make sure to toggle ON the Pin Windows, as well as the "Ask for Pattern before unpinning" option.
6. Now, open the Application you want to Pin. (If you pin an app, your Galaxy S7 won't open any other application or window, unless the unlock pattern is provided)
7. Hit the Recent Key button (which is left to the home button) to see the list of already open applications
8. Find the App to be Pinned in the list, and tap the Pin icon on the bottom right corner of the app card
9. Touch the Start button and your App will be pinned and locked on the screen