The developers of RStudio have created this wonderful package called shiny. It allows you to create little apps using R. You can deploy your app on a server or used their cloud based service. I played around with it and have created my first app and have chosen to use the cloud based solution. My first app is the BEA Data Explorer.
Since shiny allows for visualization of the data I think it is a great tool when you are exploring a data set for the first time. It helps you to get a feel for the data. This app allows me to look at the BEA data for metros. I can easily filter the data, view the relationships between two variables, and even cluster them using k-means. I would love to hear what you think of my app!