Those who use Amazon's Kindle app for the iPad, iPhone, and iPod touch can now finally access newspaper and magazine subscriptions that were previously only available to hardware Kindle users. The company announced the new Kindle for iOS feature, along with a handful of others, on Wednesday morning. Amazon claims that users now have access to more than 400 publications that can be delivered straight to their devices.

In addition to the ability to read your magazine and newspaper subscriptions through Amazon, Kindle for iOS users can now also access documents that they send to their private "send-to-kindle" e-mail address through the app. Amazon also says it has added a PDF reader that will open PDFs from within Mail or Safari on the device, or PDFs transferred via iTunes. "The PDF reader is enhanced with support for PDF table of contents and thumbnail navigation for quickly jumping through the document," the company said via e-mail.

The new features are available today via an app update through Apple's App Store, but when I tested it on my iPad to see if I could access a New York Times subscription on my account, the app claimed there were no subscriptions to be had. Amazon did not respond to our request for clarification on this point by publication time, so it's unclear as to why this is happening.

Have any of you been able to access your periodical subscriptions through the iOS app yet, or are you running into the same problem?

(Update: Some are telling me that NYTimes restricts its subscriptions to hardware Kindles, and that's the reason why the subscription isn't showing up.)