There are lots and LOTS of other books and programs out there to teach your child to read. My 3 1/2 year old can now read words with regular sounds and short vowels (we're working on vowel blends now). She'll be reading books before kindergarten, and we haven't done a lot of work at all(about 10 minutes a day for the last month) I suggest, if you are looking at teaching a very young child to read, buy or check out from a library one of the reading books by Sidney Ledson. He taught his 2 and 3 year old daughters to read in about 45 days, and his method is easy, fun and doesn't require any special equipment! All you need is his book! His method is really flexible too.
If you just want to teach your child phonics, my favourite books are Phonics Pathways and The Ordinary Parents Guide to Teaching Reading.
But the BOB Books where what really got my daughter 'reading', and loving the fact that she could read.
You have to decide - why do you want the children to read this early? And how much time of their lives and yours do you want to devote to this practice right now? Are you interested in spending several hours a day on just drilling reading, or are the other things in that child's life more important?