Here are seven apps for starters, each with a specific list of benefits.

Goodreads has more than 12 million books in its database and more than 10 million members who actively share their favorite books, reviews, and insights with the Goodreads community. There is a Goodreads app for Apple (iOS 4.3 and later) and for Android devices (1.5 and later) that syncs with your Goodreads account to keep track of the books you’ve read, what’s on your reading shelf now, and what’s on your wish list. Use the app’s bar code scanner to capture book data when you’re at a brick-and-mortar store and then add the titles to your wish list. The app also includes a list of more than 2,000 free downloadable titles from the public domain. You can also add comments on the books you’re reading, rate and recommend books, join online book clubs, and get listings for literary events wherever you roam.

LibraryThing, a social cataloging service, includes more than 82 million books that its 1.7 million members have catalogued. Its search capabilities reach into the Library of Congress, international Amazon sites, and more than 700 world libraries. LibraryThing offers a LibAnywhere (or Library Anywhere) app for Apple (iOS 4.3 and later) and Android devices (2.0 and later). You can add books to your personal library on the site, add tags to book entries, and even use the Library of Congress or Dewey Decimal systems to organize your own personal collection. The app can locate your closest participating libraries and lets you search their catalogs, place a book on hold, view the library’s upcoming events, and contact a librarian, if needed. (Note: You’ll need to check to make sure your library is partnered with the app in order for it to function effectively.)

Copia bills itself as “the world’s first social eReading experience,” a platform that connects you with other book lovers. The Copia 2 app for Apple (iOS 5.0 and later) and Android devices (2.2 and later) lets you buy ebooks, take and share notes, and read and discuss ebooks with others. The app, which supports 10" tablets, includes a library of your book collections (those you’ve read or are planning to read) and free access to seven ebooks. You can track your reading with the progress bar, share book insights with others in the Copia community, rate books, read ebook notes that your Copia friends have written, and launch threaded discussions with them in the book margins.

Zola Books, a socially integrated ebook retailer and publisher, opens the doors to a collection of 40,000 ebooks. Its app for Apple devices (iOS 5.1 and later) calls it “the first truly social, truly open” ebook reader. The app lets you read ebooks, send messages to friends, rate books, and download books for offline reading. With Zola, you can also network with writers, publishers, and independent booksellers; plus, you can pledge to have a percentage of your purchase go to the independent bookstore of your choice.

Bookish is a newcomer to the collaborative e-reading arena that Hachette Book Group, Penguin Group, and Simon & Schuster launched earlier this year. Its app for Apple (iOS 4.3 and later) and Android devices (2.2 and later) can read EPUB and PDF files of ebooks purchased on other websites and can save those titles to your Bookish library. Bookish can help you find your next good read using its recommendation engine, book lists, and exclusive articles from notable authors, while offering 18 genre pages to browse through for more ideas.

eBookMall, an ebook retailer, has more than 400,000 ebooks on its digital shelves. Although it doesn’t have an app of its own, it piggybacks on Readmill’s app for Apple devices (iOS 6.0 and later). Once the app is downloaded, you can select from its long list of free ebooks and share any of your text highlights with other readers. The app supports EPUB and PDF ebook files, which can be loaded into the app, and there is also an option to store your content in the cloud. Readmill keeps track of what you’re reading, how long until the end of the book, and how many books you’ve read. The app also points you to its selection of free ebooks, but it cannot read ebooks bought in the iBookstore (even though it is an Apple app) or from any other closed-ecosystem store. Now in the works is enhanced functionality for the app that will let you read library titles.

TheReadingRoom.com is a growing virtual community where readers can find new authors and a collection of 7 million books that its users and established reviewers have endorsed. TheReadingRoom.com’s app for Apple (iOS 4.3 and later) and Android devices (2.2 and later) is designed to foster ebook reading and community building. You can join the community to view book recommendations, read book reviews from The New York Times and other sources, and discover new authors. TheReadingRoom.com platform offers book clubs, author interviews, and digital shelves to display your own collection.