Marco Arment's popular iOS reading app Instapaper got a huge update this morning with the release of version 4.0 in the iTunes App Store. Visually, the iPad app has been completely redesigned with a new grid UI that shows off headlines and a brief article preview, and the iPhone app has visual tweaks throughout and drops the top menu bar on articles to open up more reading space. The Friends sharing section is now similar to Flipboard, another personalized reading app for iOS. Friends still shows your friends' likes from within Instapaper, but now lets you browse all links shared from your friends on Tumblr, Twitter, and Facebook.

Version 4, one of the biggest Instapaper releases yet, has hundreds of other tweaks and additions that should be welcome to regular users of the app, including author and publish date information on articles, pop-up Wikipedia definitions for terms, footnote popups, article multi-select for queue management, improved archive and delete options, a new App Directory that shows Instapaper-compatible apps, a fresh app icon, and more. Additionally, subscribers to Instapaper's $1/month plan get search access to the full text of every article ever saved to Instapaper. .