So installed this now, as we are trying to figure out what is chewing bandwidth on one of my mobile users. Only issue I see is that it records all of the bandwidth consumed and doesn’t allow me to see what was used over which interface, so have asked her to clear the logs before she leaves today so that I can get an accurate monitor of what applications could be chewing the data while she is on the mobile network (3G)
We don’t have uncapped mobile contracts here 
and data is seriously expensive.
But otherwise great little app, hope it helps me track down what is killing her data.