You don't see Flo Rida showing up a ton as a guest rapper on the songs of other stars—though his Wiki discography page shows a lot more all-around guest appearances than you ever would have imagined—which makes sense, because he's not a very good rapper. But it appears that Rihanna has cottoned to the Rida, as she keeps allowing him to show up on "remixes" to her lead singles. After last year's "We Found Love" cameo, Flo again shows up on Ri's lead single in 2012, with Unapologetic's "Diamonds."
Flo's contributions, as usual, are not considerable. He basically has his verse cut-and-pasted onto the song before Rihanna's opening "Shine brite like a di-a-mond," and his lyrics are not supremely memorable—though he actually does a decent approximation of Rihanna's voice and flow as he sing-raps "Baby you're a diamond / shinin' / No silver in the lining," and he probably deserves some credit for slowing down his traditional yammering to match the pace of the song. For Flo Rida, the effort is acceptable.
Still, we can't help but wonder who else she could've gotten to be on this remix instead. Anthony Gonzalez of M83, maybe?