Excel Online does support Apps for Excel, but they have to be inserted into the spreadsheet using Desktop Excel. Once you do that, they will show up in the spreadsheet when you view it in Excel Online. We plan to add the ability to insert apps using Excel Online in the near future.”
“We've got a similar function in desktop Excel - the WEBSERVICE function. We want to bring that to Excel Online as well, and we will - once we've addressed some of the more commonly requested features.
In the meantime, there are some Apps for Excel that grab stock quote data that you can try. You need to insert them into the spreadsheet using Desktop Excel, but once you do, they will work in Excel Online.
Here is a few that might be interesting: http://office.microsoft.com/en-us/store/results.aspx?qu=stock&avg=zxl150”
A year ago we announced that Excel Online and each of the applications that make up Office Online were destined to become a comprehensive productivity experience on more browsers and devices—not just companions to the desktop applications. Since then we’ve released several major updates and many minor updates, and today I’m sharing another significant step forward! (Note that these changes will roll-out worldwide over the course of the next few…