Thank you Grinity.
I've just checked his progress records on the program when he started typing without checking his fingers. Ah, it said he was typing at WPM speed of 23. I'm not sure his current speed is, but he types much quicker now. (around 30-40 WPM I guess...)

For some reason, he learned to type quite effortlessly. I thought it might be a huge challenge for him to type due to his fine/gross motor coordination issues. He was diagnosed with Oral Motor Dyspraxia, (oral motor control disorder- he was totally nonverbal until age 3.5) and still has gross motor coordination problem. So, it was a wonderful surprise!