My previous post on Office 365 and Sharepoint Online was meant for any user with a SharePoint Online account.
This post, however, is strictly for the developers. So, let me re-run the Sharing your Developer site for external users well before so that at the time of publishing your App for Office 365, you do not get any error.
After creating your Developer Site in your Sites Collection (Please refer to the previous post for help in creating one), click on the newly created Developer site (after it has been provisioned, of course) and check the Let External people access...check box so that your new site that you will use to develop Apps for Office 365 so that the apps can be shared with a public link.
Alright, now for the basic requisites. You need Napa or Visual Studio with Office 365 API installed in your computer. The former is like a dream come true. All you need to do is browse to your newly created Developer Site and click Build an App
and you are ready to program for Office 365 from your browser !!
'Napa' on Cloud is the coolest feature of Sharepoint Online!
Once you have decided to build an Office 365 app, that is clicked on Build an app, a new page will urge you to Add new project to the Napa cloud.
The next step is to select the app type and give it a name for your Office 365 app to be created on the cloud !
Let me show you a Task Pane app for Excel that I created.
When I used to work on employee data that had date columns that had to be individually typed, I sometimes used to embed the Calendar object to refer to for the dates. But to be able to input date directly? That required VBA Macros and Macros that made the screen flicker and the Sheet sometimes refresh could be annoying and was obviously not the best solution.
So, as soon as I saw the Task Pane template, I got excited.
Yes, this is what is needed - simpler than an Add-In, more reliable than a Macro and more efficient to distribute across the organization via Sharepoint !!
Below is a Task Pane for Excel that allows you to input date from a calendar !
All you now need is to select the date from the calendar and set the date to the Excel cell!!