Welsh, Carson, Anderson & Stowe, among other investors, has completed a $100 million funding of Revel Systems, an iPad point-of-sale platform. The round includes an initial $65 million from WCAS, which will extend an additional $25 million equity line. As part of the deal, firm partner Sanjay Swani will join the company's Board. Serving grocery, retail and restaurant establishments, Revel will use the funds to grow support and operations to meet demand for its platform. The company, which had raised a $10.1 million Series B in June 2013, reportedly earned a $450 million valuation with this latest round.