I am using a iphone 4s as a camera and have been for 2 years. I need to update the (free) app, Presence. The itunes app wants me to sign in with a super old ID. I go to settings and change the itunes ID. The app still wants me to sign in with the old ID. Is there something I can do other than uninstall and install 15 apps under my current ID? ?? Maybe you have to set up family sharing between an old and new ID? Not getting an answer sort of tells me. If it is doable I think someone would bother to post the answer.