I believe so... They are advertised on this site and you can even get a 50% discount off any subscription if you buy the Gengo Talking Japanese Dictionary.
Given all of that, it'd be a huge coincidence if they didn't make them! Perhaps a moderator can clarify though.
I'm wondering if anyone has used them though and can tell me if they're any good. Also, I'm wondering how on earth you can actually get the 50% subscription coupon through the iTunes music store, since I don't believe there's any mechanism available for that sort of thing.
Edit: I just checked and the iPhone apps are made by 'Innovative Language Learning', who appears to be the parent company that runs all of the '[Language]Pod101' sites, etc.
http://www.innovativelanguage.com/produ ... Dictionary