带有WatchKit扩展名的父应用是iOS 8及更高版本吗？

I've got an existing iOS app, which still supports iOS 7, I would like to keep that for some time. But I would also love to have an Apple Watch app - is it possible that the app extension for WatchKit is iOS 8 and the parent iOS is iOS 7 or do I have to lift that to iOS 8 as well?I've got an existing iOS app, which still suppo