Yes, you can use Excel spreadsheets as a drawing tool to convert images into pixel art with little effort.
If you ever need to create diagrams for your PowerPoint slides, these simple design tips should help make your diagrams looks even better.
You can add drawing objects like flowcharts, arrows, callouts, banners and even freehand scribbles to your documents in Google Docs. This is very similar to the drawing canvas of Microsoft Word.
Dabbleboard is an awesome online whiteboard that turns your random mouse scribbles into perfect shapes.