Ok, not a WPX, or XAML sample in this case, but I feel the need to share a piece of news with you. After more than a year of work we've released Kezmo, an enterprise chat and team collaboration tool.
It's an alternative to products such as Slack, or HipChat, Moxtra, Quip, etc, with the caveat that it integrates task management capabilities such as those you'd find in products like Trello & Wunderlist. Providing a two in one deal which avoids context switching between apps.
On top of it it's localized to several languages, such as Spanish, Portuguese making it easier to adopt by international teams. Soon to follow are more languages.
It can be setup on premises, which is critical for organizations looking to have more control over their data, and to implement custom security policies.
It'd be really awesome if you could give it a try (it's free) and let me know what you think.