Well that was fast. Starbucks CIO Curt Garner:
Out of an abundance of caution, we are also working to accelerate the deployment of an update for the app that will add extra layers of protection. We expect this update to be ready soon and will share our progress here. While we are working on the update, we would like to emphasize that your information is protected and that you should continue to feel confident about the integrity of our iOS app. link
Funny that “an abundance of caution” equates to no longer storing usernames, passwords, and geolocation in cleartext (i.e. throwing caution to the wind).