I allowed someone to use my iTunes on my computer. They logged out and I have logged in on the computer. However, when I try and download an app for my iPhone, it shows her apple id and asks for her password. Help! Thanks.
Did you enter your password when it showed your ID and checked your account.
One other possibility is to go to the Store menu at the top, Deactivate your computer then Activate it.
Also, is this occurring when you are trying to download an application directly to your iPhone? If yes, sync your iPhone while you are logged on to your account.