If you have control over the message traffic arriving via BleTooth, the AI2 Chart and ChartData can accommodate multiple readings graphs in the same chart, in real time.
Here is a post with the particular section of the doc describing that:
In short, you send labelled text readings, one per message, in the form
v:nnnnn
a:nnnnn
where v and a are labels for volts and amps, and each nnnnn is a decimal number.