Trusted documents - This version prompts the user to confirm that they trust the workbook before allowing it to run. Once a workbook app is trusted, the user will not be prompted again.
Context menus - Context menus can now be defined much more easily compared to using the native Microsoft Excel API for context menus (i.e. CommandBars).
App settings - Apps can now define settings much more easily by creating a class that exposes configuration properties and populating them with the appropriate attributes.
Function caller information API - The runtime now passes in a new IFunctionContextAccessor interface that lets functions get a reference to the calling workbook.
Adding resource files - Local files can now be added to a project as resources.