I have 2 email addresses. The App store uses email address 2 and I can't remember the password for that. Anyway I'd rather it used email address 1. I have checked through Settings>iCloud, Settings>iTunes & App Store and both are logged into email address 1. Settings>Messages was logged into email address 2 but I've signed out of that. Even so I still can't get the App Store to let me login with email address 1.