"All 1.8 million images from the ARTstor Digital Library are accessible for iPad, iPhone, iPod touch, and Android-powered devices to registered Artstor users!" There’s no need to download special software, just go to ARTstor from the Library's home page to access the mobile site.
"Artstor Mobile provides read-only features such as searching, browsing, zooming, and viewing saved image groups. Also try the Flashcard View, which allows you to test your knowledge by viewing the image without textual information, and then flipping the image to reveal the image record."
"JSTOR’s interface automatically adapts to the screen size of a device without requiring a separate mobile URL or any device configuration. Just go directly to www.jstor.org on a smartphone or tablet, and the screen will adjust accordingly!"
"UPCC [University Press Content Consortium] books are accessible on any mobile device with a web browser and the capability to open PDF files, such as the iPhone or iPad. [Project Muse is] currently in the process of developing a new interface for mobile devices that will improve a user's experience when searching and retrieving MUSE content on mobile devices."
EndNote Online also has a mobile version of its bibliographic resource. While this does not have the full functionality of the online site, you can log in with your EndNote username and password and access your EndNote account.