210 Digital Wars calculation suggested that, with Android's current growth trajectory, by the end of 2012 the patent royalties could be a billion-dollar business. 52 And that would be almost pure profit. App patents Microsoft might have a business in demanding software patent payments from handset makers, but the category carries a sting in the tail. As smartphones took off, two US companies with software patents granted in the United States ­ Lodsys and MacroSolve ­ began suing developers in the United States and beyond, claiming infringement of their intellectual property. Apple and Google had licensed the patents involved ­ for Lodsys, it involved in-app purchases, a function available only through Apple's own SDK ­ and said their protection extended to the developers. By mid-July 2011, British developers were withdrawing their apps from sale in the United States across all platforms. Shaun Austin, a British developer based in Cheltenham, tweeted: `selling software in the US has already