I know this is a bit of an old thread, but I was also going to suggest Speech Blubs.
My now 3 year old absolutely loves it. I downloaded it when he was around 2y2m. He was very delayed in speech - by the time he turned two he was barely using 2 words consistently. We started speech therapy at 2y2m. Within around 6 weeks he suddenly had a long list of words he was using regularly.
His speech development gradually grew into phrases and sentences, but he still does not pronounce labial sounds consistently (b, m, p).
I don't know if it was the speech blubs that helped more or the speech therapy. Probably both. We stopped speech therapy after about 8 months though because he started getting very resistant to what the therapist was trying to get him to do and point blank refused to cooperate, so i couldn't see any benefit to the sessions at all. He was talking pretty fluently by then, but still not using labial sounds where they should be used (a "bin" he calls a "nin", for "big" he says "gig". But he can say purple and mom and mamma etc, so he can say them, just doesn't when there's a different consonant involved in the same word).
Since stopping speech therapy he has started using speech blubs much more regularly. Of his own accord. He absolutely LOVES it.
I will probably pick up therapy again later this year, but with a different therapist, to try and work more on the labial sounds, but I figure for now at least speech blubs is drawing his attention to words and their makeup and different sounds.