SharePoint 2013 Client Side Rendering
I was looking for ways to add a custom field type using SharePoint app approach. I found the following two good article that explain how it can be done. With the app model, the custom field type control is just not possible any more. So, this is the way. http://blogs.technet.com/b/sharepointdevelopersupport/archive/2013/04/09/how-to-add-a-custom-field-to-blog-posts-in-sharepoint-2013.aspx http://code.msdn.microsoft.com/office/Client-side-rendering-JS-2ed3538a Client side rendering actually helps to easily change how a list renders its items as well. All this technique should work for Office 365 or SharePoint online.