The 100,000 coins is enough to buy one three-star pack of player cards, which deliver one rare player and four current NFL players. "Madden Social Cash" is the only currency that can buy four- or five-star player packs, additional plays, or "energy," which governs the number of offensive drives you may play in a certain span, so, basically, they're giving you a free three-star pack of cards, or two two-star ones and some change. My impressions of Madden NFL Social explain its economic structure in greater detail.
The three-star pack I picked up with my money delivered defensive end Chauncey Davis of the Bears (rated 73), center Kevin Matthews of the Titans (67), cornerback Devin McCourty of the Patriots (83) and, for my "rare" card, offensive tackle Michael Oher of the Ravens. Yep, not a single offensive skill position player in any of that. And the lone "base" or non-special card in that pack was 73-rated Vince Wilfork. Then again, buying a two-star pack returned me a mix of defensive and offensive linemen and a cornerback too. I think high rated difference-maker positions on offense must come in the four- or five-star packs.
The rest of the title update adds support for the larger-screen of the iPhone (and iPod Touch) 5, plus some stability changes and bug fixes. A previous title update added achievements to the game. The app, available for iOS devices, is free to play.