Photoshop Touch needs to be purchased and downloaded separately.
This is terrible. Just can't believe that.
I'm playing devil's advocate here but both iTunes and Google Play are two completely different and closed electronic marketplaces with no mechanism that I know of that allows Adobe to freely license PS Touch to subscribed (paying) CC users. The most logical way I can think of at this point in time is to provide a rebate.
The small consolation is that PS Touch does work with CC once its bought (and you don't have to pay for updates; PS Touch has come a long way since version 1.0 since they keep refining/adding features).