There are a number of ebook readers available for Android, but if you want a Holo-friendly option, your best bet is to rely on Google Books or the latest version of Aldiko. Now there's another competitor making its way over from iOS that seems to blend in just as well, if not more so. Readmill for Android offers a reading experience that's easy on the eyes and - since it's not tied to a bookstore of its own - your wallet.
When you first open up Readmill, you will be prompted to sign in either with Facebook or an email address. After this, you can either import DRM-free epubs from your device or explore the free selection of books that are available. You can also upload ebooks to Readmill.com in order to sync them across all of your devices. The app only displays text (that's right, no book covers) and offers day and night views for easy reading regardless of the time of day.
The app will work on any device running Android 4.0 or later, and it's available for free. If you're not already beholden to the likes of Amazon, Barnes & Noble, or Google, this alternative reader might just be attractive enough to stop you from selling your soul to a single distributor.