Can you set up the bluefruit to be a client (i.e. query the BLUE SC device which acts as a server)? There should be tutorials around on how to do this. If you can do this then you just need to capture the cscmeasurement characteristic data which is in the form of 11 bytes - you want the last two (sorry if you already know this).
byte[0] - single byte value tells you whether wheel (1), crank (2), or both (3) data are present in the message. You are interested in cadence so you would hope this value is either 2 or 3
byte[1] through byte[4] - this is a 4 byte value that tells you the total number of wheel revolutions (not crank)
byte [5] and byte[6] - this is a 2 byte value that tells you the number of 1/1024 of a second since the last wheel revolution event. This period can then be used to calculate the RPM of the wheel.
byte [7] and byte[8] - this is a 2 byte value that tells you the total number of crank revolutions
byte[9] and byte[10] - this is a 2 byte value that tells you the number of 1/1024 of a second since the last crank revolution event. This period can then be used to calculate the RPM of the crank. This is the value you want but need to convert this value to an RPM measurement.