Moon reader is my favorite, has lots of settings, and the paid version will read to you using text to speech. If you do it right you don't need a tablet or an ebook reader. The 4g screen works just fine.
But there's a trick you need for commercial e-books. I found that the commercial e-readers like BN-Nook (free) were designed for tablets and will put useless margins around the text that you can't get rid of. This is fine for tablets but not a 4g as you end up with about a paragraph per screen. Moon Reader will get rid of the margins but won't read copy-protected ebooks like the ones you can buy on line.
There is a free program called Calibre
, however available for PC, Mac, and Linux. This program will strip the copy protection so you can read the ebooks on something like Moon Reader without those margins eating up screen space. It works great.
There are a lot of free e-books around if you don't mind older stuff.
SGS 4g running ... er,check the message content.