I was looking for activities for "The Snowy Day" and came across a site that might be helpful for kids with speech/language delays. It is thebudgetslp.
It has activities and also lists apps.One activity that looked cute was to write the targeted letters on snowflakes, put them on the floor and have the child play musical chairs. Whatever sound he lands on, he says. I think that would be fun for sight words/vocabulary words too.