From the GP team, the New version of Dynamics Business Analyzer Windows 8 App has been published to the Microsoft Store. I’m going to update my version right now!
New version of Dynamics Business Analyzer Windows 8 App has been published to the Microsoft Store. – Inside Microsoft Dynamics GP – Site Home – MSDN Blogs
Reporting & BIInstall, Upgrade & AdminMicrosoft & the GP Ecosystem
Archived post from 2013. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.