RuuviStation: combine values of several sensors into single graph

It would be useful to be able to create custom graphs, for example showing humidity values of several sensors in single graph. Or creating a view which shows humidity values of several sensors in one page, each in their own graph. Or having two Y-axes for data from one or multiple sensors, e.g. Y1 = temperature, Y2 = humidity.

These custom charts could be accessible in app main page with user defined name.