ESL Flow, and some of the links to which it took me, represents the greatest treasure trove of online ESL materials I've seen in my 17 years of ESL teaching. I spent 25 minutes (this visit) trying various features of the site out. I took an interactive grammar assessment exam most of my students would find challenging. I found some excellent "Icebreaking" exercises, and I followed the links to the BBC World Service and to Transparent.com, where I signed up for free monthly newsletters in 3 foreign languages.
The quality of the content on this site is rather high; it will most certainly enhance student learning, up to the Advanced-Intermediate level.
Finally, first-time users and computer novices will find the site easy to use.
Don Dunham (Assistant Professor of English / Broome Community College (New York)