Yes, Boost Mobile's newest phone, as well as their first touchscreen phone, is the Samsung Seek. Though it has a touchscreen, the phone is also a "slider" that makes use of a full QWERTY keyboard.
HotHardware: In Samsung's world, the talk of the Galaxy is all about the recently unveiled S4 with its plethora of fancy new features and hardware enhancements, but don't go hating on its predecessor. The Galaxy S III is still a capable smartphone, which is why Boost Mobile and Virgin Mobile are so excited to announce that they're now carrying Samsung's previous flagship device.
TechCrunch: "Back at CTIA 2010, Motorola announced the world’s first rugged Android handset with iDEN push-to-talk functionality: the i1. At launch, Motorola was only willing to spill the beans on one carrier who’d be getting the handset: Sprint.
We just unearthed some pretty irrefutable proof that someone else will be getting the i1: Boost Mobile. Yep — say hello to the first pre-paid Android handset in the US"