Why Develop for Android Tablets?

If you're already developing apps for Android mobile devices, developing for Android tablets is the next logical venture for you. If you're not developing for Android mobile devices, the real question should be, “Why not develop for Android tablets?” Do you want your app to be available to millions of users worldwide? Do you want to publish apps as soon as you're done writing and testing them? Do you like developing on open platforms? Do you have a great app in mind more suited for a tablet than a smart phone? If you answered yes to any of these questions, I think you have your answer, but in case you're still undecided, keep reading, and I'll explain what I mean.

Using your existing Android code

If you're an existing Android developer, pay attention: You can use the same code you wrote for your other Android apps on the Android tablet. Yes, that's right, you can develop for both devices with the same code. With Android, you can have your cake and eat it, too! The only differences you'll encounter are some nuances between device screen sizes and how to handle the various new features in both platforms. Android has always aimed itself as being as backward-compatible as possible, and if you refrain from using newer features, you can write apps that work on previous versions. I cover these differences throughout the course of this book.

Major market share

As a developer, you have an opportunity to develop apps for a booming market that's expanding on a daily basis. As of this writing, Android is set to outpace many other carriers in market share in coming months. With so many users, it's never been easier to write an application that can be downloaded and used by real people. And the Android Market puts your app right into your users' hands with little fuss: Users don't have to go searching the Internet to find an app to install. They just simply go to the Android Market, and they have access to all your apps. Because the Android Market comes preinstalled on most Android devices (I discuss a few exceptions later), users typically search the Android Market for all their app needs. Your app's number of downloads can soar in just a few days.

Quick time to market

With all the application programming interfaces (APIs, which are the entry point into the features of the Android framework) that Android comes packed with, developing full-featured applications in a relatively short time frame is easy. After you sign up with the Android Market, just upload your apps and publish them immediately. “Wait,” you may ask, “are you sure?” Why, yes, I am! Unlike other mobile marketplaces, the Android Market has no app-approval process. All you have to do is write apps and publish them.

For more information on publishing your apps to the Android Market, see Chapter 10.

Open platform

The Android operating system is open platform, meaning that it's not tied to one hardware manufacturer or one provider. As you can imagine, the openness of Android has allowed it to gain market share quickly. All hardware manufacturers and providers can make and sell Android devices. The Android source code is available at http://source.android.com for you to view or modify. Nothing prevents you from digging into the source code to see how a certain task is handled. The open-source code allows phone manufacturers to create custom user interfaces (UIs) and add built-in features to some devices. Because everyone can access the raw Android source code, all developers have an even playing field.

Device compatibility

The Android operating system can run on many devices with different screen sizes and resolutions. Additionally, Android comes with tools to help you develop applications that run on a variety of devices, screen sizes, and resolutions. And Google allows your apps to run only on compatible devices: If your app requires a front-facing camera, for example, only devices with a front-facing camera will be able to see your app in the Android Market. This arrangement is known as feature detection.

Exploiting mashup capability

A mashup combines two or more services to create an application. You can create a mashup by using the camera and Android's location services, for example, to take a picture with the exact location displayed on the image. Or, use a maps API with the contact list to show all your contacts on a map. (See “Integrate Google APIs,” later in this chapter.)

You can easily make a ton of apps by combining services or libraries in new and exciting ways. And with all the APIs that Android includes, it's easy to use two or more of these features to make your own app.

Here are a few other mashups to get your brain juices pumping. All this stuff is included for you to use, and it's completely legal and free.

• Geolocation and social networking: Social networking is the “in” thing right now. Suppose you want to write an app that tweets your current location every 10 minutes throughout the day. Use Android's location services and a third-party Twitter API (such as jTwitter), a timer in Java, and you can do just that.
• Geolocation and gaming: Location-based gaming, a great way to really put your users into the game, is gaining popularity. A game might run a background service to check your current location and compare it with the locations of other users of the game in the same area. If another user is within a mile of you, for example, you could be notified, and you could challenge her to take control of that given region. None of this would be possible without a strong platform, such as Android and GPS technology.
• Contacts and Internet: With all these cool APIs at your disposal, it's easy to make full-featured apps by combining the functionality of two or more APIs. You can combine contacts and the Internet to create a greeting card app, for example. Or you may just want to add an easy way for your users to contact you from an app or enable users to send the app to their friends. This is all possible with the built-in APIs.

The sky is the limit. All this cool functionality is literally in the palm of your hand. If you want to develop an app that records the geographic location of the device, you can with ease. Android really opens the possibilities by allowing you to tap into these features easily. It's up to you, as the developer, to put them together in a way that can benefit your users.