If you know HTML, CSS, and JavaScript, you already have the tools you need to develop Android applications. This hands-on book shows you how to use these open source web standards to design and build apps that can be adapted for any Android device -- without having to use Java. Buy the print book or ebook or purchase it in iBooks.

Thanks to mobile phones, we have moved from virtually no one having access to information, to virtually everyone having access to the vast resources of the web. This is arguably the most important achievement of our generation. Despite its overarching importance, mobile computing is in its infancy. Technical, financial, and political forces have created platform fragmentation like never before, and it’s going to get worse before it gets better.

Developers who need to engage large and diverse groups of people are faced with a seemingly impossible challenge – "How do we implement our mobile vision in a way that is feasible, affordable, and reaches the greatest number of participants?" In many cases, the answer is web technologies. The combination of advances in HTML5 and mobile devices has created an environment where even novice developers can build mobile apps that improve people’s lives on a global scale.

Google's Android operating system is a compelling addition to the mobile computing space. In true Google fashion, the platform is open, free, and highly interoperable. The development tools are full-featured and powerful, if a bit geeky, and run on variety of platforms.

Carriers and handset manufacturers have jumped on the Android bandwagon. The market is beginning to flood with Android devices of all shapes and sizes. This is a double-edged sword for developers. On one hand, more devices means a bigger market. On the other hand, more devices means more fragmentation. As with the fragmentation in the general mobile market, fragmentation on Android can often be addressed by building apps with HTML, CSS, and JavaScript.

I’m the first to admit that not all apps are a good fit to be built with web technologies. That said, I see a lot of apps written with native code that could’ve just as easily been done with HTML. When speaking to developers who aren’t sure which approach to take, I say this:

If you can build your app with HTML, CSS, and JavaScript, then you probably should.

Using open source, standards based web technologies gives you the greatest flexibility, the broadest reach, and the lowest cost. You can easily release as a web app, and debug and test it under load with thousands of real users. Once you are ready to rock, you can use PhoneGap to convert your web app to a native Android app, add a few device-specific features if you like, and submit to the Android Market—or offer for it download from your web site. Sounds good, right?

Who Should Read This Book

I’m going to assume that you have some basic experience reading and writing HTML, CSS, and JavaScript (jQuery in particular). I will be including some basic SQL code in Chapter 5, Client-Side Data Storage so a passing familiarity with SQL syntax would be helpful but is not required.

What You Need to Use This Book

This book is going to avoid the Android SDK wherever possible. All you’ll need to follow along with the vast majority of examples is a text editor and the most recent version of Google Chrome (a cutting edge web browser that’s available for both Mac and Windows at You do need to have the Android SDK for the PhoneGap material in Chapter 7, Going Native, where I explain how to convert your web app into a native app that you can submit to the Android Market.

Conventions Used in This Book

The following typographical conventions are used in this book:


Indicates new terms, URLs, email addresses, filenames, and file extensions.

Constant width

Used for program listings, as well as within paragraphs to refer to program elements such as variable or function names, databases, data types, environment variables, statements, and keywords.

Constant width bold

Shows commands or other text that should be typed literally by the user.

Constant width italic

Shows text that should be replaced with user-supplied values or by values determined by context.


This icon signifies a tip, suggestion, or general note.


This icon indicates a warning or caution.

Using Code Examples

This book is here to help you get your job done. In general, you may use the code in this book in your programs and documentation. You do not need to contact us for permission unless you’re reproducing a significant portion of the code. For example, writing a program that uses several chunks of code from this book does not require permission. Selling or distributing a CD-ROM of examples from O’Reilly books does require permission. Answering a question by citing this book and quoting example code does not require permission. Incorporating a significant amount of example code from this book into your product’s documentation does require permission.

We appreciate, but do not require, attribution. An attribution usually includes the title, author, publisher, and ISBN. For example: “Book Title by Some Author. Copyright 2008 O’Reilly Media, Inc., 978-0-596-xxxx-x.”

If you feel your use of code examples falls outside fair use or the permission given above, feel free to contact us at .

Safari® Books Online


Safari Books Online is an on-demand digital library that lets you easily search over 7,500 technology and creative reference books and videos to find the answers you need quickly.

With a subscription, you can read any page and watch any video from our library online. Read books on your cell phone and mobile devices. Access new titles before they are available for print, and get exclusive access to manuscripts in development and post feedback for the authors. Copy and paste code samples, organize your favorites, download chapters, bookmark key sections, create notes, print out pages, and benefit from tons of other time-saving features.

O’Reilly Media has uploaded this book to the Safari Books Online service. To have full digital access to this book and others on similar topics from O’Reilly and other publishers, sign up for free at

How to Contact Us

Please address comments and questions concerning this book to the publisher:

O’Reilly Media, Inc.
1005 Gravenstein Highway North
Sebastopol, CA 95472
800-998-9938 (in the United States or Canada)
707-829-0515 (international or local)
707-829-0104 (fax)

We have a web page for this book, where we list errata, examples, and any additional information. You can access this page at:

To comment or ask technical questions about this book, send email to:

For more information about our books, conferences, Resource Centers, and the O’Reilly Network, see our website at:
Site last updated on: November 17, 2010 at 11:11:58 AM PST