receiver.js extended to show colours according to ranges (in/low/high), showing the in range, hover-tooltip of datapoints... 

receiver.js extended to show colours according to ranges (in/low/high),
marks at the "In-Range-boundaries,
hover-tooltip of datapoints,
 and fixed range for y-axis (With variable y-axis, small changes can look drastic and high variablility can lead to underestimation of current trend).

Added zoom-button to window.html
Moved Export-button to the top
Added handlers for the zoom to app.js