NEW YORK (CNNMoney) -- Watch your backs, Apple and Google: Amazon is getting into the app store game.
The online marketplace went live late Tuesday with the Amazon Appstore Developer Portal, a self-service tool inviting mobile developers to submit apps for the store's upcoming launch. On the site page, Amazon said the store will open for business later this year; a company representative said it has no target date ready to announce yet.
Amazon (AMZN, Fortune 500) is setting its sights on the Android app market -- a savvy first step. In contrast to Apple's tightly controlled and highly curated iPhone app store, Google's Android Market is a wide-open Wild West, which allows creators to publish their apps without any vetting.
Amazon will have an approval process for the apps it lists in its store. It plans to charge developers a $99 annual participation fee, which it will waive for the first year. It will also take a 30% cut of the sales price on each app, in line with the fees Apple and Google charge. Like those markets, Amazon will also feature free apps that users can download without charge.
Amazon said it will use its formidable marketing muscle to push apps out to its millions of e-commerce customers.
"The sheer number of apps available today makes it hard for customers to find high-quality, relevant products -- and developers similarly struggle to get their apps noticed," the company said in its pitch to developers. "The convenience of using an existing Amazon.com account will make it simple and easy for customers to purchase your apps -- both online and on their mobile devices."
Amazon said it will reject apps that contain pornography or other offensive content, and it plans to publish "maturity" ratings for those it sells.
Initially, the market will only sell Android applications, but Amazon is leaving the door open for expansion.
"I can't speculate, but it wouldn't surprise me," Amazon spokeswoman Sally Fouts said, when asked whether the store will expand to other app ecosystems.
Right now, Apple (AAPL, Fortune 500) has by far the most active app ecosystem, with more than 300,000 iPhone apps available. Google (GOOG, Fortune 500) has 200,000 applications stocked up in its Android Market, while rival platforms BlackBerry, Palm webOS and Windows Phone 7 trail far behind.
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