My son is severely autistic but knows his way around his ipad and does the games. is there a way to lock these so we can use his ipad for communication as he is non verbal but can type.

Ipad, the model is MC979X/A, it's storage capacity is 12.9 GB, Available storage 9.7 GB and version number 8.1.3 (12B466) I am looking for a way to lock the games so we can use this Ipad for communication with my non verbal son. He can type and we also have an app called proloquo2go. my problem is he will go for the games and refuses to use the communication program so I wanted to used some way of locking the games and use them as a reward after he has completed his work