PS Touch is an app by itself in its own marketplace. (Both iTunes and Google Play are closed systems.) The only valid way I could see Adobe giving it to you for "free" is maybe through a rebate.
Unless Adobe does otherwise, updates that include new features are free. Picked up PS Touch from the beginning (v. 1.0) and haven't had to pay for anything beyond the $9.99. (I don't have a CC subscription.)