Microsoft's ExcelMashup.com assists to create apps.

Microsoft’s Excel team has been working at sprucing up user' experience with spreadsheets. It has built the ExcelMashup.com , which let users create apps, just like mashups, with an embedded Excel workbook on a host web page. Apps can be created using Excel Services JavaScript API, workbook stored on a public SkyDrive folder, and standard web technologies. The blog states that, “for example an app that combines Excel and Bing Maps that creates a Destination Explorer mashup that shows stats on specific travel locations.”

The site claims to serve as a "one-stop-shop for learning about how to get started developing rich, interactive mashups on your web site quickly using Excel Web App and the power of Excel formulas for calculation." The site has several tabs to get started , learn more about the technologies used and so on. It also features the Interactive Code Snippets that lets you try out various elements of the script before adding them to the project.