Searching for people is another extremely useful feature, but it takes a little more work than keyword or location searches. Google and Apple deploy smart algorithms to pick out faces that appear in multiple photos, but they rely on you to tell them who's who. In Google Photos, tap the search box, and the app will show you a row of faces that show up in your photo library. Scroll through these until you find the person you want to identify. Next, tap the thumbnail, then Add a name to match the image with one of your contacts. Once you've done that, you can search for that person using the standard search tool. In Apple Photos, find a photo that includes a person you want to identify and swipe up. Tap the thumbnail of the person under People and choose Add Name. As you type, the app will match the name to a person in your contacts. To view all the photos of a certain friend, open the front screen of the app, tap Albums, then select People.