For me, it means I no longer have to worry about having my iPhone or iPad with me, if I'm out and want to spend a little quality time with Clash of Clans. For others without iOS-devices, it means they have an opportunity to experience the game.
Getting started is easy, for the new Android player. Head over to Google Play and download Clash of Clans. It's a free app, though be warned -- once you get going, you may feel tempted to buy "gems" and speed up your progress. Plenty do. It didn't become the second-highest grossing iPhone app without plenty of people buying gems and making other in-app purchases.
Migrating from iOS
For the existing iOS player, you'll need to do a one-time linking of your iOS device to your Android device. Don't worry. You won't be leaving iOS behind if you do this. The link just allows you to play on either platform, whenever you want.
As with a new player, you'll need to download Clash of Clans for Android from Google Play and go through the short tutorial after the game loads. Currently, there's no way around this. Don't stress over picking a name. When you import, your existing name and existing village will overwrite whatever you do in the tutorial.
When the tutorial is over, you can use the gears icon in the lower-right of your screen to reach the "Link a device" option in Settings:
That option will let you indicate that you're on the new device you want to import a game onto. After a few steps, it will ask for a link code. You'll get that link code by following the same procedure on any iOS device where you already play Clash of Clans. Take the code from your old device, put it into your new device, and eventually your existing village will appear on the new device:
For more detailed instructions, Supercell has a linking guide in its forums. Note that you'll need to do this before reaching Town Hall Level 4 on the new device, before making any purchases, and only if you've connected your device to Game Center in iOS and Google+ in Android.
Bringing up additional Android devices
Once you've installed Clash of Clans on any Android device, you shouldn't need to go back to your iOS device for a fresh link code to get it going on an additional Android phone or tablet.
Instead, just install Clash of Clans as normal, go through the tutorial, then select the "Google+ Sign-In" option. That will let you pick your Google account which, if associated with a Clash of Clans village through Android already, will then allow you to bring that village into the new device.
I used the steps above to successfully bring my Clash of Clans village from my iPad into my Nexus 10. Then I also added it to my Nexus 7 and my Galaxy S4. You play exactly the same on Android as you do on the iPhone or iPad. It really is a well-done, consistent experience.
Going between iOS and Android
One of the best things, when it comes to using Android it isn't a one-way street. You can play the same village on both Android and iOS devices after doing an import. You can go back-and-forth between platforms as often you like, easily, after the one-time setup is done.
Whenever you open a village on any device, that device will temporarily lock out all other devices. Anyone who has played Clash of Clans on multiple iOS devices is used to seeing the "Connection Lost" message when they open their village on a new device. Now, that works across both Android and iOS, so that you never have your village open on more than one device at the same time, keeping everything in sync.
For example, I opened my village up on my iPad, then went to my Nexus 10 and opened it there, which automatically signed me out of play on my iPad. I then opened it on my Nexus 7, which signed me out of play on the Nexus 10. When I went back to the iPad, I was signed out of the Nexus 7.
To be clear, I didn't have to repeat any of the initial setup to do this. That's a one-time thing on each device. After you've established your village on any device, that's it. Just launch the app to play, and whatever device you have active will log you out of any active sessions on other devices.
Still no clashing for Windows Phone users
It's still bad news for one of my sons, unfortunately. A , he can't play Clash of Clans when away from home on his phone like his older brother can.
How about Clash of Clans for Windows Phone? "Maybe one day," Supercell tweeted in response to someone who asked, but for now, "we have no plans."