We've all dealt with it before: you hand someone your phone to show them a photo, and the jackass swipes forward and/or backward to look at your other photos. That's a huge no-no, but unfortunately there are still people out there who didn't get the memo (or are just too damn rude to care). Fortunately, there's a way to keep this scenario from happening ever again.
It's a simple app called Focus, and it basically puts other photos under a PIN code, so when someone tries to swipe left or right, they're greeted with this message:
There are two versions of Focus: an ad-supported, free variant; and a paid version that costs a dollar.