The Power BI Designer is a new companion application for Power BI.
It is a standalone Windows Desktop application that can be downloaded from the Power BI site.
This application combines Power Query, Power Pivot Data Model and Power View into a seamless experience that will allow customers to build their Power BI elements in an offline fashion and then upload to the Power BI Service.
The Add-ins for Excel 2013 and later are still available and customers can continue to use that to model their data and build reports.
The Power BI Designer will be another option and allow customers with an older version of Office to be able to create reports.
