By Bill Rigby SEATTLE (Reuters) – Microsoft’s impending purchase of Mojang, the Swedish developer with 100 million players of its open world Minecraft game, is more aimed at pulling users onto the software companys obscure mobile platform than its better known PC system or Xbox game console. The software companys Windows Phone system has only 2.5 percent of the worlds smartphone market, and its Surface tablet barely more, according to tech research firm IDC. Enter Minecraft, which is the top paid app both on Apple Incs iOS and Google Incs Android systems. Microsoft will unveil a $2.5 billion deal to buy its owner on Monday, according to a source briefed on the matter.