Justin Bieber, New York Times Invest in Revamped Recommendations App Stamped

Stamped is rolling out on Thursday a dynamic new version of its recommendations app for iPhone and iPod touch devices. The company has also announced a web companion and a new round of financing from some noteworthy names, including singer Justin Bieber, comedian Ellen DeGeneres and The New York Times Company.

Stamped, which is staffed primarily by former Google employees, first launched on the iPhone in November. The app allows you keep track of and share the things you like with your friends, such as restaurants, books, films and other apps. You can also tap into your friends' recommendations and those of well-known tastemakers, from chef Mario Batali (an advisor to the startup) to Rolling Stones film critic Peter Travers. (For more on how the app works, read our initial review here.)

The startup released an update to the app in March that enabled users to view the recommendations of not only their friends and tastemakers, but also friends of friends and the entire Stamped network. It was designed to provide a better on-boarding experience for first-time users whose friends are not — and might never become — active users of the app.

Shortly after releasing that update, Stamped's team decided to scrap the entire app and "build something bigger," Robby Stein, one of Stamped's three co-founders, told Mashable in an interview at Stamped's New York office earlier this week. "There's not one piece of [old] code in the new version," he said.

The app's function and aesthetic is essentially the same, but it's much more dynamic. Previously, recommendations from all of your friends were organized by recency; now they're categorized and contextualized under "The Guide," a new vertical that lets you quickly surface suggestions by activity: eat/drink, watch, listen, read and download.

Each recommendation comes with a useful third-party integration: When you explore your friends' music recommendations, you can play the entire album by logging in with your Spotify or Rdio account. Come across a good restaurant recommendation? Check out the menu, view photos from Instagram (Instagram co-founder Kevin Systrom is an advisor to the startup) and book it on OpenTable. You can also add movie and TV shows to your Netflix queue, buy movie tickets through Fandango and purchase books on Amazon.

You can also see how your friends are interacting with your stamps — whether they're listening to that album you recommended, or checked out the menu for the bakery you stamped last week. That may not sound like much, but it gives the app a lively, social flavor it lacked previously. It's also easy to spot when a number of your friends want to do the same thing, so that you can suggest you all check it out together.

Stamped has also released a read-only web app that makes it easy for users to share recommendations with friends who don't use Stamped. Eventually, Stein says, they'd like Stamped users to be able to do everything on the web they can do with the mobile app.

If that's not enough news for you, the startup is also announcing that it has raised a round of funding from a roster of notable names: Bain Capital Ventures, Google Ventures, Metamorphic Ventures, singer Justin Bieber, comedian Ellen DeGeneres, American Idol host Ryan Seacrest, The New York Times Company and Columbia Records, among others.

What's next for this red-hot startup? The team is waiting on feedback from its users to determine the next steps, but did indicate an interest in deepening integration with third-party services like Spotify and Netflix in the future. There's "no timeline" for an Android app, says Stein, but he imagines it will appear "sometime next year." The ultimate goal? To become "the central place for reviews," a service Stein believes could attract 100 million users. How's that for ambition?

Image courtesy of iStockphoto, theasis