I discovered an app. I believe it's both on the Android network as well as the iOS (apple). It is called All About Sounds and is a great practice tool for kids working on articulation sounds. There are two versions - the "lite" version and the full version. The "lite" version is FREE, but only has phonemes: b, ch, d, dz, and f. It also only does the initial position. However, if your child is working on any of those sounds in the initial position, then it would be perfect for you! It has a "lesson mode" where the child plays a matching game with pictures starting with his/her sound (i.e. bag, baby, baboon, ball, banana, etc). Each time a picture pops up, the child hears the proper pronunciation of that word. The game mode is a matching game, but the child doesn't hear the words each time. It's a great way for the child to hear the correct pronunciation and then try to copy it.
From what I read (I have not bought the full version), the full version has all phonemes and in all positions. It is $0.99 and could be a great resource for some practice in the car or at home!
Even if your little one isn't working on articulation, matching is still a fun game for kids and this will be themed with a particular sound! It's always good exposure for kids to be listening for the first sound of a word.