The Amazon Kindle for Android has finally arrived, and I’m not sure why it took so long. Amazon seemed like a good team player when Android devices first hit the market, with an app or two coming standard on several early devices. The Amazon shopping tool and mp3 store made up for the lack of iTunes and wide range of apps that were specific to the iPhone, though the Kindle was left out of the Android party.

All the while, Amazon was building its app empire on Apple devices, fighting to maintain its presence in light of iTunes, eBooks and Apple’s own threatening deals with publishers for its default e-book readers. Barnes & Noble has begun to carve out its own niche, with the Nook reader’s recent price cut starting an all-out pricing war. The Nook also runs on Android, giving Barnes & Noble its own access to Google’s mobile users.

I’m sure Amazon had its reasons for taking its time with the Kindle release on Android, but it’s already lacking some of the features for iOS devices. Earlier this week, Amazon announced that its iPhone Kindle app will support video, giving Apple just one more thing to worry about. From Wired,

“Like the other Kindle flavors, the Android version will keep your reading organized and synchronized across all your devices via Whispersync, let you make and view annotations and buy titles from the Kindle store. Also like the other version, the Android Kindle app is free to download (find it in the Android Market). What you don’t yet get are the audio and video extras announced for iOS devices yesterday.”

As Google pushes its Android platform, the constant stream of new devices and rapid expansion beyond cell phones, the war over dominating the mobile scene gets bloodier. From platform owners to handset makers, the fierceness of these battles has created a dizzying array of new things for developers and consumers to try out. It can be great for small businesses, as a new economy presents a global marketplace for the exchange of just about anything. They’ll just have to deal with the volatile nature of watching the new mobile gods draw lines in their sandbox.