For those who wanted to see the solution that is built as part of the walkthrough, I've uploaded it to OneDrive. Download and unzip the file, open the Solution in Visual Studio 2015 or a VS 2013 with the latest updates, and you should be all set! I recommend watching the video before downloading the solution, so that you can follow along in "the building of" before seeing the full thing.
Some reference links:
- Documentation on our new APIs: https://aka.ms/officejsdocs. In particular, I would recommend reviewing the overview article, at https://github.com/OfficeDev/office-js-docs/blob/master/excel/excel-add-ins-programming-overview.md.
- Q, one of the several main Promise libraries. The page has a great explanation for promises, as well: https://github.com/kriskowal/q
- My blog post that I'd mentioned, on using a webservice from within an Office Add-in: https://blogs.msdn.com/b/officeapps/archive/2013/06/05/create-a-web-service-for-an-app-for-office-using-the-asp-net-web-api.aspx
- My blog post on publishing (similar to what I'd covered, but a little more in-depth) https://blogs.msdn.com/b/officeapps/archive/2014/01/15/publishing-apps-for-office-and-sharepoint-to-windows-azure-websites.aspx
- StackOverflow questions tagged with [office-js]. http://stackoverflow.com/questions/tagged/office-js
Hope you find this useful!
~ Michael Zlatkovsky, developer on Office Extensibility team, MSFT