Mind you, it may well be that an iphone or some other smartphone will scale the whole page down to fit the screen size, but that isn't exactly responsiveness. Anyway, I haven't tried in on a phone.
The image formats used for web; png, jpg and gif will work in Wow Slider.
Inger, Norway
My work in progress:
Components for Site Designer and the HTML Editor: https://mock-up.coffeecup.com