The Role of Google
Although Android is officially the brainchild of the Open Handset Alliance, Google is the clear leader when it comes to implementing Android itself, as well as providing the necessary ecosystem for it to grow.
The Android Open Source Project
Google's efforts are summarized in the Android Open Source Project. Most of the code is licensed under Apache License 2, which is very open and nonrestrictive compared to other open source licenses, such as the GNU General Public License (GPL). Everyone is free to use this source code to build their own systems. However, systems that are proclaimed Android compatible first have to pass the Android Compatibility Program, a process ensuring baseline compatibility with third-party applications written by developers. Compatible systems are allowed to participate in the Android ecosystem, which also includes the Android Market.
The Android Market
The Android Market was opened to the public by Google in October 2008. It's an online software store that enables users to find and install third-party applications, or apps. The market is primarily available on Android devices, but also has a web front end where users can search, rate, download, and install apps. It isn't required, but the majority of Android devices have the Google Android Market app installed by default.
The market allows third-party developers to publish their programs either for free or as paid applications. Paid applications are available for purchase in many countries, and the integrated purchasing system handles exchange rates using Google Checkout. The Android Market also gives the option to price an app manually on a per-country basis.
A user gets access to the market after setting up a Google account. Applications can be purchased via credit card through Google Checkout or by using carrier billing. Buyers can decide to return an application within 15 minutes of the time of purchase for a full refund. Previously, the refund window was 24 hours, but it was shortened to curtail exploitation of the system.
Developers need to register an Android developer account with Google, for a one-time fee of $25, in order to be able to publish applications on the market. After successful registration, a developer can start publishing new applications in a matter of minutes.
The Android Market has no approval process, instead relying on a permission system. Before installing an application, the user is presented with a set of required permissions, which handle access to phone services, networking, Secure Digital (SD) cards, and so on. Only after the user has approved these permissions is the application installed. The system relies on user honesty. This approach isn't very successful on the PC, especially on Windows systems, but on Android, it seems to have worked so far; only a few applications have been pulled from the market due to malicious user behavior.
In order to sell applications, a developer additionally has to register a Google Checkout merchant account, which is free of charge. All financial transactions are handled through this account. Google also has an in-app purchase system, which is integrated with the Android Market and Google Checkout. A separate API is available for developers to process in-app purchase transactions.
Challenges, Device Seeding, and Google I/O
In an ongoing effort to draw more developers to the Android platform, Google introduced promotions in the form of challenges. The first of these, called the Android Developer Challenge (ADC), was launched in 2008 and offered relatively high cash prizes for the winning projects. The ADC was repeated the subsequent year, and was again a huge success in terms of developer participation. There was no ADC in either 2010 or 2011, probably because Android now has a considerable developer base and needs no further promotions aimed at getting new developers on board.
As an incentive for its developers, in early 2010 Google started a device-seeding program. Each developer with one or more applications on the market, that had more than 5,000 downloads and an average user rating of at least 3.5 stars, received a brand new Motorola Droid, Motorola Milestone, or Nexus One phone. This promotion was very well-received within the developer community. It was initially met with disbelief, though, as many considered the e-mail notifications that came out of the blue to be an elaborate hoax. Fortunately for the recipients, the promotion turned out to be real, and thousands of devices were sent to developers around the world—a great move by Google to keep its third-party developers happy, make them stick with the platform, and potentially attract new developers.
Google provides the special Android Dev Phone (ADP) for its developers. The first ADP was a version of the T-Mobile G1 (also known as the HTC Dream). The next iteration, called ADP2, was a variation of the HTC Magic. Google also released its own phone in the form of the Nexus One, originally available to end users. Although not initially released as an ADP, it was considered by many as the successor to the ADP2. Google eventually stopped selling the Nexus One to end users, and it is now available for shipment only to partners and developers. At the end of 2010, the latest ADP was released—a Samsung device running Android 2.3 (Gingerbread), called the Nexus S. ADPs can be bought on the Android Market, which requires you to have a developer account. The Nexus S can be bought via a separate Google site at www.google.com/phone.
The annual Google I/O conference is an event that every Android developer looks forward to each year. At Google I/O, the latest and greatest Google technologies and projects are revealed, among which Android has gained a special place in recent years. Google I/O usually features multiple sessions on Android-related topics, which are also available as videos on YouTube's Google Developers channel. At Google I/O 2011, Samsung and Google handed out Galaxy Tab 10.1 devices to all regular attendees. This really marked the start of the big push by Google to gain market share on the tablet side.