Booth Library subscribes to electronic collections from many vendors but there are three that make up the majority of D&E's electronic sources. They are: EBSCO; JSTOR; and U.S. Government Documents.
The pdf readers outlined on the Intro tab are a solid "vendor neutral" option for reading a pdf, but if you are focusing on the resources from a specific vendor and/or want to send sources to folders you have set up on a vendor website, then you could download their app.
The EBSCO Mobile App is available via Apple or Android.
There is a JSTOR app on Play Store for android devices, however "JSTOR’s interface automatically adapts to the screen size of a device without requiring a separate mobile URL or any device configuration. Just go to JSTOR via the Library's website and when viewing content on a smartphone or tablet, the screen will adjust accordingly!" (JSTOR support page)