An oldie but goodie!! QR Codes can be used with any device that has a QR reader on it. This is a great way to help students get to websites quickly and accurately. There are a ton of activities out there using QR Codes. A valuable resource is Teachers Pay Teachers.
We use QRStuff.com for a generator and we like the reader apps:
QR Code Reader (iOS and Android)
i-nigma (iOS and Android)
