A friend of mine asked me that today. He has an Android smart phone. It's not a Kindle or a Nook, so he figured he couldn't read my crime fiction e-books on his 'droid.
Amazon and Barnes & Noble must've seen this question coming, because they have FREE (yep, free) apps for all Android and Apple smart phones. You download the Amazon Kindle app or Barnes & Noble Nook app, then purchase e-books to read.
Not only that, but they also offer free PC and Mac downloads for computers. They're really easy to install.
When you do, don't forget to download my "Cleansing Eden" crime novel!