As expected, Amazon has opened its new Appstore for Android today, letting Android users purchase and download apps via the website or through a new native Android app.

As Sarah Perez noted yesterday in her report on the store's launch, the new marketplace for Android apps may be an important step forward for both Android users and developers. The Amazon store will compete directly with the official Google Marketplace, often criticized for poor search and discovery - a drawback for those looking to buy and build Android apps.

The Amazon Shopping Experience

Amazon brings its long history of e-commerce experience to bear here, and the Amazon Appstore will utilize many of the popular Amazon store features - personalized recommendations, reviews, and 1-click payments.

One of the most interesting features of the new store is the ability to "Test Drive" an app before you buy it. When you visit the website, you'll be able to control the app through your computer, giving you a chance to see if the app really does what it says or what you want.

The store will also offer a "Free App of the Day" special, which as the name suggests, means making an app that typically costs money available to download for free. This discounting is made possible through Amazon's new pricing agreement with developers. Unlike the Google and Apple App Stores, Amazon sets the price here, not developers. Developers do get to set a list price, and will still get a cut of that price, even if their app is made free as part of Amazon's daily special.

To mark the launch of the store, today's free app is an exclusive - Angry Birds Rio. So here's how you can get that app - and get started with the new Amazon Appstore.

A Walkthrough: Installing the Appstore for Android

1. You'll first need to download the new native app. If you enter your mobile phone number, Amazon will text you a link so you can download it onto your phone.

2. Download and install the new "Amazon_Appstore.apk." This will give you the new Appstore app.

3. Sign in with your Amazon account. This will link your payments to your Amazon account.

4. You can purchase apps either through the Amazon website or via the new app. If you do the former, launching the Appstore on your Android will complete the download and installation. Like the official Android appstore, this will also be how you update your apps to new versions.

Quality Over Quantity

As Sarah Perez pointed out yesterday, the Amazon Appstore will have a more stringent review process than Google's official Android Marketplace. That means, ideally, fewer but better quality apps. My initial reaction: it isn't just the quality of the apps that's better here; it's the whole shopping experience. Amazon will suggest relevant apps and best-selling apps, for example, something that's bound to make this store a boon for Android.

Android users, do you think you'll be using Amazon's new Appstore?