> a lot of reinforcement has to happen at home
No app, parents and caregivers have to become the therapist. Depends on your child's age but these are the resources we used:
https://teachmetotalk.com/
https://www.hanen.org/
> The closest app is $200 just to show him flashcards and says an audio clip
Could you please provide the app(s)? We use this one every now and then:
https://speechblubs.com/