I have reservations about how useful spending a whole lot of time on phonics in isolation is to English language learning. However, I do believe that limited time on explicit phonic instruction can be helpful.
Since I’ve started highlighting sites now and then that have been on my webpages for awhile, I wanted to point out what I think is the best activity there for reinforcing phonics knowledge.
It’s Wordbuilder from I Know That. I have the link on my English For Beginners page under Phonics. It’s in the middle of that section.
Clicking on the link will lead you to a list of different letter sounds. Once you click on a sound, you get a pop-up asking if you want to join I Know That. Just have students click on “Maybe Later” and then they will be sent directly to the activity.
The university of Iowa has an excellent phonics resource at http://www.uiowa.edu/~acadtech/phonetics/#.
It seems to be intended for linguistics students, so the average English student will either need a strong grounding in the IPA or guidance from a teacher first.