Both Happy Flock and SpeedTiles were written several years ago using the Cocos2D game engine and built as 32-bit binaries.
Two big changes. First, Cocos2D development was halted. (We've moved onto Unity3d for newer projects, but if you want to stay with Cocos, check out Cocos2d-x. Both are great.) And second, iOS 11 requires apps to be 64-bit.
So as of right now, neither Happy Flock nor SpeedTiles will run on iOS 11 devices.
We're figuring out the best way to bring both games to 2017. If you want to be informed about when we publish iOS 11 compatible-updates, please contact us, and we'll let you know as soon as they're available.
Our apologies to the fans of these games. And thank you for your patience.