The last step in becoming an Android game developer is getting your game to your players. There are two possible routes:

• Take the APK file from your project’s bin/ folder, put it on the Web, and tell your friends to download it and install it on their devices.
• Publish your application on Google Play, like a real pro.

The first option is a great way to let other people test your application before you throw it on the Google Play store. All they need to do is get a hold of the APK file and install it on their devices. The real fun starts once your game is ready for prime time.

A Word on Testing

As we’ve seen in the previous chapters, there are various differences among devices. Before you publish your application, make sure it runs well on a couple of common devices and different Android versions. There are a few ways to approach this problem. You can either purchase an array of devices with different hardware capabilities running different versions of Android and test in-house, or you can pay for any one of the new Android testing services. We are lucky enough to have several phones and tablets, covering different device classes and generations, for testing. Depending on your budget, though, neither of these approaches might be an option. You might have to rely on the emulator (but not too much, as it is indeed unreliable) or preferably on a couple of friends to help you out.

Another way to test your application is to put a beta version on the Google Play store. You can clearly mark your application as beta in its title so that users know what to expect. Some users, of course, will gladly ignore all the warnings and still complain about the quality of your potentially unfinished application. That’s just how life is, and you’ll probably have to deal with negative and possibly unjustified comments. Remember, though: Your users are king. Don’t get angry at them—try to figure out how to improve your application instead.

Here’s a list of devices we commonly use for testing applications before release:

• Samsung Galaxy Leo/I5801, 320×240-pixel screen
• HTC Hero with Android 1.5, 480×320-pixel screen
• HTC G1 with Android 1.6, 480×320-pixel screen
• Motorola Milestone/Droid with Android 2.1, 854×480-pixel screen
• HTC Desire HD with Android 2.2, 800×480-pixel screen
• Nexus One with Android 2.3, 800×480-pixel screen
• HTC Evo 4G with Android 2.2, 800×480-pixel screen
• Samsung Galaxy S with Android 2.2 and 4.0, 800×480-pixel screen
• Samsung Nexus S with Android 4.1, 800×480-pixel screen
• Samsung Galaxy Nexus with Android 4.1, 800×480-pixel screen
• Samsung Galaxy Tab 10.1 with Android 3.1, 1280×800-pixel screen
• Google Nexus 7 Tablet with Android 4.1, 1280×800-pixel screen

As you can see, we cover quite a range of screen sizes/resolutions and device generations. If you look for outside testers, make sure you get coverage of most of the device generations outlined here. Newer devices should, of course, also be on your list, but less for reasons of performance testing than for compatibility testing. If nothing else, make sure you at least are testing on a few of the official Google devices, which include the Nexus 7, Galaxy Nexus, Nexus S, and Nexus One devices. If your game isn’t working well on these devices, you are sure to have trouble heading your way if you don’t make changes.

Finally, you have to accept the fact that you can’t test your application on all the devices out there. You are likely to receive error reports that are inexplicable and might well stem from the fact that a user is running a custom ROM that doesn’t behave as expected. In any case, don’t panic; this is normal to some extent. If the problem with errors goes overboard, though, you’ll have to try to come up with a scheme to battle it. Luckily, Google Play helps us out in that regard. We’ll see how that works in a bit.

Becoming a Registered Developer

Google makes it really easy to publish your application on the Google Play store. All you have to do is register an Android developer account for a one-time fee of $25 USD. Assuming you live in one of the countries on Google’s long list of supported locations for distributing applications, this account will allow you to post your apps on Google Play. Whether you can post free apps only or both free and paid apps depends on which country you live in. To post paid apps, you must live in one of the countries on Google's somewhat shorter list of supported locations for merchants. Google also has separate lists of countries to which you can distribute apps freely and countries to which you can distribute paid apps. Google is working hard to expand these lists so that your apps can reach the entire globe.

Your Google Play Store publisher account is tied directly to a Google account.  Unless restrictions have been lifted, you may not separate the publisher account from the Google account. It’s important to take that into account when deciding between registering with an existing account or registering with a new, dedicated account.  Once you’ve made that decision and have your Google account ready, visit https://play.google.com/apps/publish/signup and follow the instructions given there to register for the Google Play store.

In addition to your Android developer account, you will also need to register for a free Google Checkout merchant account if you want to sell your applications. You will have the option to do this during the developer account sign-up process. We’re not lawyers, so we can’t give you any legal advice at this point, but make sure you understand the legal implications of selling an application before you do so. If in doubt, consider consulting an expert on the matter. We don’t mean to scare you off by this, as the process is pretty streamlined in general, but you should be prepared to keep your government’s tax department apprised about your sales activity.

Google will take a percentage of your hard-earned money (30% as of this writing) for distributing your app and providing the infrastructure. That seems to be pretty much the standard cut taken by all the application stores on the various platforms.

Signing Your Game’s APK

After you have successfully registered as an official Android developer, it’s time to prepare your application for publication to Google Play. In order to publish your application, you have to sign the APK file. Before you do that, you should make sure everything is in place. Here’s a laundry list of things to do before signing the APK file:

• Remove the android:debuggable attribute from the <application> tag in your manifest file or set it to "false".
• In the <manifest> tag, you’ll find the android:versionCode and android:versionName attributes. If you have already published a previous version of your application, you must increase the versionCode attribute, and you should also change the versionName attribute. The versionCode attribute has to be an integer; the versionName attribute can be anything you like.
• If your build target is equal to or higher than SDK level 8 (Android 2.2), you should also make sure the <manifest> tag has the android:installLocation attribute set to preferExternal or auto. This will satisfy your users by ensuring that your application is installed on external storage if possible.
• Make sure you only specify the permissions that your game really needs. Users don’t like to install applications that seem to demand unnecessary permissions. Check the <uses-permission> tags in your manifest file.
• Confirm that you set the android:minSdkVersion and android:targetSdkVersion attributes correctly. Your application will be visible on Google Play only on phones that run a version of Android equal to or higher than the specified SDK version.

Double-check all of these items. Once you are done, you can finally export a signed APK file that is ready to be uploaded to Google Play by following these steps:

1. Right-click your project in the Package Explorer view and select Android Tools Export Signed Application Package to launch the Export Android Application wizard. You’ll be greeted with the Project Checks dialog, shown in Figure 15-1.

   

   Figure 15-1.  The signed export dialog

2. Click the Next button to move to the Keystore selection dialog, shown in Figure 15-2.

   

   Figure 15-2.  Choosing or creating the keystore

3. A keystoreis a password-protected file that stores the key with which you sign your APK file. Since you haven’t created a keystore yet, you’ll do so now in this dialog. With the “Create new keystore” radio button selected, just provide the location where you want to store the keystore, along with the password that you will use to secure it. Click the Next button to move to the Key Creation dialog, shown in Figure 15-3.

   

   Figure 15-3.  Creating the key for signing the APK

4. To create a valid key, you have to complete the Alias, Password, and Validity (years) fields, as well as enter a name in the First and Last Name field. The rest of the fields are optional, but it’s a good idea to fill them out nevertheless. Click Next, and you are shown the final dialog (see Figure 15-4).

   

   Figure 15-4.  Specifying the destination file

5. Specify where the exported APK file should be stored, and make sure to note the path. You’ll need it later when you want to upload that APK. Click Finish.

When you want to publish a new version of a previously published application, you can just reuse the keystore you created the first time you went through the wizard. Launch the wizard, and when you get to the Keystore selection dialog shown in Figure 15-2, select the “Use existing keystore” radio button, provide the location of the keystore file you created previously, and provide the password for the keystore. When you click Next, you’ll see the “Key alias selection” dialog, shown in Figure 15-5. Just select the key you created previously, provide the password for it, click Next, and proceed as before. In both cases, the result will be a signed APK file that is ready for upload to Google Play.

So, you’ve created your first signed APK—congratulations! Now we’ll throw a wrench into the works and inform you about the multiple APK support. For a single app, you can create multiple APKs that use device capability filtering to get the “best fit” for each user who installs your app. This is a great feature because it means you can do things like the following:

• Ship specific image sets that are compatible with specific GPUs.
• Have a limited feature set targeted for older versions of Android.
• Ship larger-scale graphics for larger screen sizes and regular-scale graphics for all others.

Google will surely add more filters as time goes by, but just the set outlined here enables you to really hone in on a target device (like tablets) without having to jump through too many hoops to keep the download at a reasonable size for first-generation device support.

Putting Your Game on Google Play

It’s time to log in to your developer account on the Google Play website. Just go to https://play.google.com/apps/publish and sign in. You’ll be greeted with the interface shown in Figure 15-6.

This interface is what Google calls the Android Developer Console, which is what you caught a glimpse of when initially registering. Now we’re ready to actually use it. Clicking the Upload Application button at the bottom of the screen will let you do that, by opening the Edit Application screen. Let’s go through some of the sections of the Edit Application screen, the first of which, Upload assets (on the Product details tab), is shown in Figure 15-7.

More On The Developer Console

Once your game is published on Google Play, you will want to keep track of its status. How many people have downloaded it so far? Have there been crashes? What are the users saying? You can check all this out in the Android Developer Console (see Figure 15-6).

For each of your published applications, you can get a few pieces of information:

• Overall rating of your game and number of ratings
• Comments made by users (just click the Comments link for the respective application)
• Number of times your application has been installed
• Number of active installs of your application
• Error reports

The error reports are of special interest to us. Figure 15-11 shows the error reports received for the game Antigen: Outbreak.

In total, there have been one freeze and seven crashes. Antigen: Outbreak has been on the market for more than a year, so that’s not bad. You can drill down further into the specific errors, of course. The error-reporting feature of the Developer Console will provide you with detailed information about the crashes and freezes, such as the device model on which the problem occurred, full stack traces, and so on. This can be of immense help when you’re trying to figure out what’s actually going wrong with your app. Comments on the market won’t help for much more than general problem identification.

Summary

Publishing your game on Google Play is a breeze, and it has a very low barrier of entry. You now have all the knowledge necessary to design, implement, and publish your first game on Android. May the force be with you!