Sprint Corp unveiled a plan on Thursday that gives subscribers access to unlimited data for $60 a month, the industry’s cheapest unlimited data offering as the carrier attempts to reverse the decline in its subscriber base. Sprint’s new offerings are $20 cheaper than T-Mobile’s unlimited plan and are available to new and existing customers who bring in their own cellphone or pay full price for a new one. The announcement comes just hours after rival T-Mobile US launched a campaign to lure subscribers away from other carriers.