One of our favorite social commerce apps, and the first to win a Cannes Lion award, Pay With a Tweet, just received a slick makeover.

The new interface for the free app makes it easier than ever to ‘sell’ digital goodies on Twitter for the price of a tweet.

If you’re not familiar with Pay With A Tweet, it’s a free ‘social locker’ service that hides a digital file behind a custom pay with a tweet button that can be placed on any web page.  If clicked the user is prompted to tweet about the offer, and once tweeted, the goody can be downloaded.  Much copied, but never bettered, it’s simple, and it’s smart.

The new version now allows users to set a maximum number of downloads and an expiration date for the offer.  The button generator is also a lot more intuitive now.

The developers, Leif Abraham & Christian Behrendt are also offering a white labelled version for businesses and brands.  Leif has headed out West to SF after a 3 year stint at R/GA NYC.