There was an iphone version. It looked like it was well on the way last year, then sony (who now seem to own it) killed it, as they were doing it without permission.
http://www.mobile1up.com/lemmings/blog/
Lesson #1: never steal somebody else's work, spend lots of time and effort doing it, and expect whoever owns it to smile and pat you on the back.
Lesson #2: sony sucks. This would be a massive success on iphone + ipad. They should either release it themselves, or, (and more likely) license it to somebody who'll do a good job of conversion.