That's where a tweak by developer Ian Burns comes in, called GuestMode 2. Like macOS, it essentially creates a guest user that can run its own apps but can't read your sensitive messages or look at any of your files. You can even choose what apps the user has access to within the tweak settings. You can give the guest account a username, as well as have the user accounts displayed on the lockscreen like macOS. There are also multiple ways to activate the tweak, either by a button on the passcode screen, an Activator action, and more. Up until now, it has not been available for iOS 10, but it has now been released on BigBoss.
Now you will be able to protect your device from unwanted interaction on iOS 10. The tweak is free for owners of the original GuestMode (iOS 7-9), and $1 for new buyers.