There are a few different Android apps for scanning QR codes. QR Code Reader is one of our favorites: it’s simple and free, works quickly, and doesn’t blast you with advertising (unlike many rival apps).
It’s also compatible with stacks of Android devices and versions: if you have Android 2.3.3 or later you’re good to go, provided, of course, that your device has a camera. If the code you’re scanning is designed to take you to a website, you’ll also need a data signal or wireless connection.