Current favorite is PDF Expert on an iPad. I read in landscape mode, with 2 pages side-by-side, and hide most of the interface. You can then tap on the right si

Current favorite is PDF Expert on an iPad. I read in landscape mode, with 2 pages side-by-side, and hide most of the interface. You can then tap on the right side of the screen to switch to the next page. That makes it pretty close to reading a print book. And you can still highlight text to review later, like any other eBook.