San Francisco - Yahoo! on Monday released an iPhone app that weaves in story summarizing software bought from a London schoolboy last month for a sum reported to be around $30m. California-based Yahoo! announced in March that it bought the Summly app created by 17-year-old Nick D'Aloisio of Britain but did not disclose the purchase price. "The new Yahoo! app has both great technology and beautiful design front and centre," Mayer said. "We've also improved the search experience with better video and image search."