A few sf/fantasy authors who offer works free to download from their websites in PDF format:
Peter Watts, Hugo Award-winning sf
John Moore, comedic fantasy
John Dalmas, military-type sf/fantasy
Cory Doctorow, popularized the free download for free publicity to boost print sales meme
Mayer Alan Brenner, put 4 of his comic fantasy novels online for free download. Not the urban fantasy you're asking for, but maybe your friend would like to try something different.
Lewis Shiner, World Fantasy Award-winner, has put up a lot of his modern fantasy/horror-ish stuff up. Mainly short stories, but occasionally a novel.
I suggest looking into seeing if your friend can use some form of software to read ePub. Perhaps a copy of Portable Firefox with the Lucifox or ePubReader add-ons installed could be used. Actually, I'd recommend Lucifox which he could run off a USB stick without having to copy all his books into the userdata like ePubReader likes to do.
Hope this helps, and welcome to MobileRead!