Add nominal band to spark line charts
It would be nice to have some more options for the spark charts. One good addition would be a band which would show the nominal values. See the image as an example. Source.
The nice thing about this nominal band is that you always have some basic min/max scale. That way if you see if a trend or a spike, you can immediately recognize it relative size. Currently that can be difficult, e.g. because a spike might be very small, but you only notice its relative size after studying the scale. Furthermore judging the scale would require knowledge of the system to judge if this particular spike is worrying or not.
Another improvement to the spark charts would be to have the band change color if the current value is outside of the band. That way you could have 100s of graphs on a single screen and even from afar could notice if all are OK or not. Then as you come closer to the screen you can inspect the graph in more detail to see the history. Although I'm not sure if it would also work for color blind people.
Additionally the red dot, latest value and name would also be nice additions.
Finally an indication of what the time scale the spark chart is displaying would be a nice addition. For example place "Last hour" or "Last 2 days" below it. Also enable the option to combine the scales of multiple charts, such that there is no unnecessary horizontal scale clutter if there are multiple spark charts.