The Android-only app from Simple Design is one of the most popular QR code scanner apps. It’s free to use and lets you save QR codes to your phone or easily share them with friends.

Your iPhone’s built-in Camera app can scan QR codes, and it’s as easy as taking a photo. Here’s how: Open the Camera app and hold your iPhone, so the QR code appears in the viewfinder.

The Libby app has many convenient features. Set your preferences for format (e.g., book vs. audiobook), language, audience, availability and more, so you’re only searching for what you want ...