HDR is not for every photograph, nor even most photos. As has been noted if anything moves in the photo you will get ghosting. This includes leaves on trees and bushes, cars, people, animals etc. It is designed to work best in high contrast situations.
I normally leave it off until I have an occasion or reason to use it, and then I normally use HDR Pro. It is a lot slower, but 99% of the time does a better job. Additionally with HDR Pro you get some sliders right in the app to make some corrections before you save it.