Hi Mk13,
We are using Ooka Island and my son loves it. He is a language guy and we definitely got it too late (he could have used it even more at 3). But here's the interesting thing: he loves doing it even though it covers quite a bit of stuff he already knows. And that never happens - he has zero tolerance for repetition!
The game introduces all phonemes so even if your son knows the letter sounds there is still a lot of new stuff. The games are fun and I especially love the books (with comprehension questions). My son now switched to Reading Eggspress (all for one price) - tons of books there, including lots of science books!
They have a two week trial - check it out and see if he likes it.
Stef
Did you also do Reading Eggs? I am trying to decide between Reading Eggs and Ooka Island. Oooka Island has a great deal right now on HSBC but it ends tonight so I am debating what to go for. I didn't even realize there was Reading Eggspress! That might be something for my younger one (DS3) once he finally tackles the mouse. He's our advanced reader.