On that note, two things.
First, when you actually start the animation, make sure that the images are loaded first. If I hit one the demo sites with a cleared cache, the images pop in pretty bad. Use document.onload instead of $(document).ready
Second, mobile performance is dreadful. From what I understand, you have it using CSS3 animation and simply add animations into divs. My suggestion would be to default to javascript on mobile. Most mobiles don't have css animations optimized as heavily as javascript animations.
I suspect any performance issues on mobile devices are down to the plugin having to do a lot of work in the DOM, rather than the CSS3 transitions themselves being slow.
Also, it'd be interesting to know what mobile browser your seeing performance issues in. Note that Opera is unfortunately buggy when it comes to CSS3 transitions and I had to write a horrible workaround to get it working. Expect Opera to have performance issues until they fix the bug.
Second, mobile performance is dreadful. From what I understand, you have it using CSS3 animation and simply add animations into divs. My suggestion would be to default to javascript on mobile. Most mobiles don't have css animations optimized as heavily as javascript animations.