Would the new HandOff app in iOS 8 and OS X Yosemite work on iOS 7? First of all, I have an iPhone 4, meaning I can't upgrade anymore to iOS 8. I would really like to use the "Handoff" and I have a mac (Mid-2011). It can upgrade to Yosemite the new OS X. Can my Mac answer the calls, messages from my iPhone which has iOS 7?
No, you need both iOS 8.1 and OS X 10.10 for this to work.