www.boundless.com
Boundless offers free customizable textbooks. They have a variety of subject areas. In addition to the full text is the information in the form of smart notes. There are flash cards and chapter quizzes. Unfortunately, there is no chemistry or physics at this time. I looked at the biology text, which is Campbell, a very high quality bio text.
After signing up I received an email from one of the company's founders. I complained about the lack of chem and physics and was told that these would be available in the spring.
The textbook is usable on a computer or a mobile. I recommend visiting the site and signing up. I plan to make a chem and physics text available for my students ASAP. This will enable them to access a traditional text 24/7 from a mobile.
