CourseSmart, a subscription e-textbook service, released its App Store software last week. The program, entitled “eTextbooks for the iPhone,” offers 7,000 different textbooks for college students from 12 different publishers. It is free for subscribers, and the company states that students save an average of 50 percent on books.

In an interview The Wall Street Journal Monday, CourseSmart Executive Vice President Frank Lyman said the application is more of an asset than a textbook replacement.

“Nobody is going to use their iPhone to do their homework, but this does provide real mobile learning,” he said. “If you’re in a study group and you have a question, you can immediately access your text.”

The service, created in 2007, is a collaboration between six higher-education publishers. The subscription model allows students to rent textbooks, typically for 180 days. When the subscription expires, students lose access to their e-texbooks.

Amazon has attempted to break into the digital textbook realm with its larger e-book reader, the Kindle DX. The books available on the iPhone are not on the Kindle. Earlier this year, Amazon released its iPhone-optimized Kindle store, which allowed users to read books on the go. Similarly, the Barnes & Noble eReader also debuted on the platform this year.

As software makers vie for a share of the e-reader market, Sarah Rotman Epps, an analyst with Forrester Research, told the Journal that the CourseSmart offering could be a breakthrough for e-textbooks.

“Textbooks are the missing link in the e-reader content base,” she said. “The problem so far is that college students haven’t really been interested in reading on their laptops. The iPhone will help create excitement and generate awareness of e-textbooks.”