Office 2013, especially the preview version of Office Home & Student 2013 RT that comes with the Microsoft Surface tablet, changes the model for writing add-on programs. There are now Office apps and an Office app section in the Windows Store. Many of these apps are free, but it's easy to see enterprise-oriented apps being developed and charged for. Microsoft's implementation of the apps in Office 2013 is clumsy in some ways, but promising.
The screen shot here gives you a closer look at how this particular app works. Double-tapping a word starts the app (Britannica Researcher) searching for related references. In this case, there is only one related reference: "spreadsheet, computing."
Building A Mobile Business MindsetAmong 688 respondents, 46% have deployed mobile apps, with an additional 24% planning to in the next year. Soon all apps will look like mobile apps – and it's past time for those with no plans to get cracking.