Duck’s Alphabet is a phonics site that’s part of WorldWorld on PBS. It’s designed for very young learners, but would also be appropriate for English Language Learners. It’s key feature is that when users sign-up, they list their parents email address and regular reports are sent to them on their child’s activity. For older ELL’s, it would seem to me that they could just put a teacher’s email address, and then teachers could see their students’ progress.

I’m adding it to The Best Sites That Students Can Use Independently And Let Teachers Check On Progress.