Free Federal rules ebooks
The 2015 editions of the Federal Rules of Evidence, Criminal Procedure and Civil Procedure are available in .epub format, which is compatible with iPads, Nooks, Android devices and basically everything but Kindles. These books are powered by the Legal Information Institute at Cornell University Law School and distributed by the Center for Computer-Assisted Legal Instruction's eLangdell Press.
These editions of the books include: The complete rules as of December 1, 2014 (for the 2015 edition); all notes of the Advisory Committee following each rule; internal links to rules referenced within the rules; external links to the LII website's version of the US Code.
And yes, all totally free.