Sometimes you just don't have room in your bag to carry a paperback, magazine or tablet-sized e-reader device. So why not make use of the smartphone you already have with you? Your Android phone makes a perfectly good e-reader, especially with the right software.
I spent a week using four of the most popular, highly rated e-reader apps in the Google Play Store: Aldiko Book Reader, Cool Reader, FBReader and Moon+ Reader. Each app was installed and tested on a Samsung Galaxy Note II, whose 5.5-in. screen strikes a good balance between portability and page size.
Note that we have not included apps that are designed primarily to open content that lives in the cloud, or that are built to focus on a specific shopping source, such as Kindle, Nook and Google Play Books. All of these apps are designed to let you read books that you download directly onto your device.
Each of the four covered here supports multiple e-book formats, multiple typefaces and a variety of text display options.
Aldiko is a serviceable e-reader with moderate ability to customize the reading experience.
If you don't have a book ready to read on your device, Aldiko lets you browse and buy books through Feedbooks and three other online book catalogs, and lets you add additional catalogs by specifying a URL.
If you want to read a book that's already on your device, Aldiko lets you browse the device's file system and open ePub and PDF files. If you want Aldiko to save your place between reading sessions, however, you must import the book into Aldiko -- a step the other apps do automatically when you open the book.
Importing a book puts it on a virtual shelf in Aldiko's library, which you can browse by title, author, tag or collection. You can group related documents by defining your own tags and collections -- so you can have collections such as "to read" or "19th century novels," or tags such as "science fiction."
Aldiko comes bundled with a single default font, but you can download a dozen more with one tap. You can adjust font sizes in whole-pixel increments and margins in 10-pixel increments. If the standard black type and white background doesn't appeal to you, you can choose among dozens of pre-selected font and background colors, and save those selections to one of two themes, labeled Day and Night. However, Aldiko doesn't let you create your own colors via selection sliders as the other apps do.
With a book open, a tap in the middle of the screen or on the menu soft key (the common ways to bring up the settings screens for all these apps) displays icons at the bottom that let you view the book's table of contents, change the theme and set the font size. I found Aldiko's menu structure a little confusing, however. For instance, to get to the main configuration options screen, where you can change not only display options but also toggle page numbers and page turn animations, you must tap the font size icon, then tap "More."
In contrast with the other e-reader apps, Aldiko's main screen lacks a status bar that shows you how far you are through a book or chapter. You can set bookmarks that allow you to return to a specific point in a book, but you can access those bookmarks only from within each book (rather than allowing you to see them whether or not the book is open). Aldiko does let you search for a particular phrase or jump to a specific numbered page.
If you long-press to select a word or phrase, you can look it up on the Web (using Google's "define" feature), search for it within the rest of the document or share it via another app. If you have the Premium version, you can also add notes and highlights to selected text -- a feature Moon+ Reader offers in its free version.
Aldiko is light on fancy extras. For instance, it offers only a single page-turning animation -- a sliding page -- that you can toggle on or off. It also lacks any way to customize gestures to control the app, other than letting you choose to either use the volume keys or touch the sides of the screen to turn a page.
Aldiko offers fewer configuration options than the other apps, but if you want to use an e-reader for PDF files, it's the most economical of the four reviewed here, as it's the only one that supports PDF files in a free edition.