The update to the Windows Phone app starts to fulfill Microsoft's promise of closer integration between Yammer and the company's other products. This is still a work in progress, especially on the desktop, and there's clearly also scope for further integration on the mobile side too (e.g. integration with the People Hub).
Windows Phone Store description:
- Sign up for Yammer account from within the app
- Preview Word, Excel, PowerPoint & PDF attachments
- Support for higher resolutions
- Performance and security improvements
- Bug fixes including spellcheck
Yammer is a free download from the Windows Phone Store. The new version is for Windows Phone 8. An older version of the app continues to be able for Windows Phone 7.5 devices.