Android tablet spreadsheet editor: Google Docs (Google Drive)
Google Docs offers very limited spreadsheet editing capabilities. First and foremost, only spreadsheets saved in Google Docs format will open in the app, rendering it useless for editing of any desktop-created documents. Beyond that, only the most basic data-entry and row-sorting functions are supported -- and even those tasks are somewhat difficult to perform. More advanced features like text formatting, calculations, and multiple worksheet toggling are all missing in action.