This feature is available in uPortal 4.0+ and uMobile.
uPortal's mobile interface can optionally display a small number for a particular portlet indicating the number of new items associated with that portlet. This number can be used to invite the user to view items like notifications, announcements, etc.
Setting the new item number simply involves setting a portlet response property with a name of "newItemCount". For example:
Setting the new item count
int newCount = myDao.getNewItemCount(request);
response.setProperty("newItemCount", String.valueOf(newCount));
The MinimizedStateHandlerInterceptor is a particularly good place to add this logic, since it gives developers an opportunity to set the property even when the portlet may not be rendered.