In my ongoing saga with getting a Windows 8 Store app approved, I’ve been battling with a handy little tool called the CredentialPicker. Handy at first glance, anyway. It creates the Dialog layer with the standard Windows 8 appearance for logging in. One of the requirements for getting a Store app approved is that if your app requires the user to be logged in to use it, it must provide an option to register, which can be as simple as a link to register on a website. My app got rejected because I didn’t do this. Since my app is built on the Delicious API, I figured I would just find the option on the CredentialPicker for adding a link to register and get it resubmitted. A great idea in concept, until I found out that there is no such option. It seems like such an obvious ability, but no - you either use the half dozen options on the CredentialPicker or you have to completely roll your own. So a word of advice - plan ahead for how you’re going to handle this, particularly if you use a third party API that doesn’t have the ability to register in it. I sure hope this changes in future releases.