Please have a look at Scor2, which spices Scord up by some additional functions. Scord uses a deprecated API and is going to be obsolete.
If you have a song and you dont know which scale to use for improvisation Scord is the application to find out.
Scord is helpful to determine the easiest improvisation scales for a given chord progression.
During improvisation you can use one of the matching scales and leave out the missing chord tones as computed by Scord.
The Top Scale detected by Scord generally is the key of the chord progression.
Note that Scord cannot detect enharmonic change. Scord only detects chord tones missing in the scale and not vice versa. E.g. if you have a progression completely in G-Maj and there is a "B7"-Chord Scord only detects "d#" and not "d" as missing tone.
In most cases this should be sufficient.