Looks like they removed it from the App Store: "Update: 11/2/11: Earlier today we launched a new Gmail app for iOS. Unfortunately, it contained a bug which bro

Looks like they removed it from the App Store: "Update: 11/2/11: Earlier today we launched a new Gmail app for iOS. Unfortunately, it contained a bug which broke notifications and caused users to see an error message when first opening the app. We’ve removed the app while we correct the problem, and we’re working to bring you a new version soon. Everyone who’s already installed the app can continue to use it."