The online retail giant said Friday that it is now offering users a $9.99 monthly membership that gives them access to more than 600,000 e-book titles. The service, which also applies to more than 2,000 audiobooks is compatible with Kindles and apps can be downloaded on other companies’ devices including iPhones and iPads along with Android, Windows and Blackberry devices.

Previously, Amazon has offered e-book rentals with Amazon Prime membership, but that service only allows for one rental each month and it only works with Amazon devices. (While there will be no limit to how long members hold onto an e-book rental, Mashable reports that it was told by Amazon that users can only hold onto 10 digital books at a time.)

Reports surfaced earlier this week that Amazon (AMZN) was testing the Netflix-style e-book rental service, with ads for Kindle Unlimited appearing briefly on the company’s website Wednesday before disappearing.

Amazon noted Friday that the service will cover such best-selling titles as “The Hunger Games” and “Diary of a Wimpy Kid” series, among others. However, most large publishers haven’t signed on to the service, making many new and popular titles unavailable. The New York Times reports that both HarperCollins and Simon & Schuster have confirmed that their titles are not part of the new Amazon service.

Considering the limited number of books available, some early reviews of Kindle Unlimited wonder if it is worth the price. Amazon also faces competition from existing services such as Scribd and Oyster that have similar offerings at slightly lower prices. Oyster offers more than 500,000 digital books at $9.95 per month, while Scribd has roughly 400,000 titles for $8.99 per month. Oyster and Scribd also include titles from both HarperCollins and Simon & Schuster.

All three services offer a free trial month to start.