While using the new Google Sheets app I noticed a few additional tools that I do not remember being in the original Google Drive app. If you click the header of a row or column it pulls up these new options.
1) Insert Rows/Columns: You now have the option to insert a row/column before or after your selection.
2) Delete Rows/Columns: You can not delete a row/column from the app. I do not remember that being an option.
3) Sort: You can sort A->Z or Z->A from within the Sheets app.
All of these options may have been available in the Google Drive app but they are new to me.