In March of 2009, Mariner introduced Mariner Calc for iOS, becoming one of the first to offer a spreadsheet app to iPhone users and was quickly followed by a version for the iPad. Calc XLS 4.0 is a major upgrade to Calc, introducing the features of universal device support, support for 8 languages, and cloud support via Dropbox sync, among many others. At its core lies a highly advanced parser and calculation engine that sets Calc apart from other spreadsheet apps and allows the user to view, edit, and save the complicated Excel file format. Check it out here.
A powerful new Mobile Spreadsheet for iOS now available in App Store, Calc XLS 4.0 is a full-featured spreadsheet product for the iOS that can handle .xls formatted files for Excel 97 and up.