Hi,
I have recently updated the Office Web Apps Server to the June 2013 Cumulative Update (KB2817350) which was published with the new features that allow rendering of freeze pane, hide/un-hide the excel worksheet and row/columns, Header Row Snapping, Sorting, Data Validation and Autocomplete. i have followed the TechNet article (http://technet.microsoft.com/en-us/library/jj966220.aspx) to update the office web apps server. Current setup is a SharePoint 2013, SQL 2012 and Office Web Apps server. All server are installed on Windows server 2012.
3vild3vil