ITTT's online TEFL certification is a great option for students who know they want to teach abroad, but may be strapped for cash and can't afford to travel somewhere to take a course.
That was my situation. The course itself will give you a basic run-down of how to teach following 3-Stage teaching format called ESA. The course is fairly straightforward, you work through a set amount of modules, then take a final exam which is planning your own ESA format lesson. The course will do a good job at giving you an idea of how to teach a class of teenagers or adults. The method used doesn't really work well with young children, which is most of my classes. Keep in mind that every school will do things a little different. For example, the school I work at now in Taiwan wants us to use a different teaching method called PPP, it's very similar to ESA but it works better for younger learners. So the method you learn may not be what you actually use in your day to day lessons. Overall, I would say this course is a great option if you don't have a $1000+ (USD) to spend on an in-class course. However, if you have the extra, I highly advise you take an in-class program because with that, you get teaching experience. My first time ever teaching was absolute mess and it made me really wish I had that prior experience. But for what you pay, you do get some detailed lessons, activity idea, and most importantly the certification itself.
What would you improve about this program?
I think the program could be improved by focusing on a few other teaching methods like PPP and task based learning. This would help teachers go into their jobs with a better understanding of what methods will work best for different types of classes. Some schools may not care what method you use as long as you get the job done, while others are a little more picky with how teachers go about their lessons.