iOS 10 app restrictions Is there a way that I can make it that you have to put a password or fingerprint when opening apps on my iPhone? 

For instance, if I give the phone to someone and they want to try to open apps that I do not want them to use, the owner's passcode or fingerprint would required to use that app?
This has been a long "want" of iPhone users. The closest thing you can do to this is:

Go to Settings > General > Restrictions

Enable restrictions. 

You can then enter a password, (can be different from your regular pass code), and you are able to restrict certain apps and features, but not everything. It has a small list of apps (all 1st party) and a slightly larger list of features / settings.

Source: Just did it on my iPhone 7.