The update to Imbroglio with new expansion went live. It's crashing the game on launch. This didn't come up at all during testing, sometimes things work differently with Game Center (the API for high scores on iOS) when applications are released, it's annoying but I'm working on it and will figure it out. Sorry everyone!
For now you can just not download the update, but if want to play on an updated copy you can by disabling Game Center (Settings, scroll down to Game Center, slide the green bar in top right to off) and the game doesn't crash, but can't access leaderboards. (If you're running an old version of iOS you might not be able to access IAPs without Game Center active, but on current ones you can.)
Okay thanks for your patience and keep looking after yourselves!