Microsoft's Xim has been updated to 1.2.1 on Windows Phone, and brings availability to everyone. So if you were in a country that didn’t have access to Xim before, you can go download the app now!
Additionally, the upgrade brings voice verification (in addition to verification via SMS) and bug fixes.
If you are unfamiliar with Xim, it is a project by Microsoft Research that brings a unique way to share pictures with people that don't need to have the app installed. It accomplishes this by sharing links via SMS or email, to a browser 'Xim' session that offers a synced, and interactive slideshow of pictures. You can view pictures with up to 25 users simultaneously, each being able to interact with the slideshow.