Google Docs is a free, web-based word processor, spreadsheet, presentation, form, and data storage service offered by Google that allows users to create and edit documents online in real-time. It combines features from Writely and Spreadsheets, and incorporates presentation technology from Tonic Systems. Google Docs can be accessed from Android and iOS mobile devices using apps or mobile browsers to view, edit and create documents and spreadsheets up to 1GB in size.