Karma Go offers contract-free unlimited data for mobile pros

All-you-can-eat mobile data is a sweet gift for on-the-go techies, and the Karma Go gadget delivers it without a contract.Sprint, T-Mobile, AT&T and Verizon offer unlimited mobile data plans, but they come with performance caps. And in some cases, such plans are available only to people who signed up for them years ago.Karma Go delivers flexible, unlimited mobile data plans for frequent road warriors. It's a sleek, hockey-puck style device that converts Sprint's 4G LTE/3G CDMA netw