What’s the best American Sign Language app for a 2yr, that is compatible with an iPhone? That his speech therapist wants him to learn a little asl.
The very best way for him to learn is by incorporating it in to his every day life. I would suggest that you start by learning the signs he would use often (more, all done, eat, drink etc) and start signing those to him each time it comes up (basically each time you would vocalize it). You’ll be surprised by how quickly he catches on.