Digital Trends – College students, rejoice! Access to massively discounted textbooks just got a little easier with Fridayâs late-night release of the Kno textbook app for the iPad. The Kno app offers customers âthe worldâs largest selection of over 70,000 titles at 30-50% off the list price.â As we all know, 30 to 50 percent off a text book can buy a lot of Ramen.