A small but powerful chart trace improvement (CF marker)

[drws]

I find the simple rectangular spectrum traces in Sparrow-WiFi very useful. The view is very clear when there are many networks around.

LinSSID has trapezoidal traces which only looks better if there aren't many networks. But it also uses one very simple and brilliant supplement - the central frequency marker, as per the picture:

What's so brilliant about it is that one can see many important radio channel parameters right away in the chart. In the example above I can quickly read that the first network has a bandwidth of 40MHz without the secondary channel and that the second network is 20MHz and uses an upper-bound secondary channel. Simple and powerful, so probably a great idea for Sparrow-WiFi.