With one fell swoop, Twitter has confronted privacy concerns, returned missed features to its mobile audience, and opened its information network up to even more tablet-toting folks.

Twitter for iPhone and Android received updates Tuesday. The fixes address previously identified shortcomings, and optimize Twitter to run on Android tablets.

Twitter released a version of its application for the Kindle Fire on the Amazon Appstore today. The company also promised that the Barnes & Noble Nook Store will get a Twitter app on Thursday.

Both iPhone and Android applications now alert the mobile Twitterer before accessing her address book to find friends. Should the Twitter user navigate to the “Find Friends” feature in the Discover portion of the app, she will find a message that reads, “We will securely upload your contacts to help you find friends and suggest users to follow on Twitter.” The user must then click “OK” before proceeding.

The addition of the alert comes just a week after VentureBeat uncovered evidence showing that a slew of iPhone applications, Twitter included, access the user’s mobile address book without first requesting permission.

Twitter’s mobile apps also now include a much-loved shortcut feature of yore that allows a person to swipe a tweet to interact with it. The swiping action brings up a shortcut screen that includes reply, retweet, favorite, share, and user profile-viewing options. The feature should (again) appeal to the power Twitterer.

iPhone application users may appreciate the returned abilities to copy and paste the text of tweets and mark all direct messages as read.