Roy and Bertrand Sosa, brothers who founded prepaid card provider NetSpend Corp., have formed Mpower Venture LP, a venture-capital fund designed to invest in companies that help financially underserved consumers around the world. Mpower announced last week that it has invested in Sapphire Mobile Systems, a Philadelphia-based company that provides mobile-banking and mobile-payments products. Under the terms of the investment, Mpower will rename the company Mpower Mobile Inc. and move its headquarters to Austin, Texas. Mpower Ventures also announced an investment in Rev Worldwide, which is based in Austin. Rev Worldwide comprises three companies–RevEurope Payments Ltd., Rev Latin America Inc. and Rev Asi Pacific–that provide payments-processing and marketing services and distribution to payments companies in their respective regions.