Thanks muneer. This is very useful to know. So for all heart rate monitors (as an example) they have the UUID 0000180D-0000-1000-8000-00805f9b34fb regardless of the brand?.
For some reason I was thinking that the UUID would be different for different brands of speed sensor, hence I would have to find out the UUID from the specific sensor being used. But if it is the same then that is great! I can use the UUID base and just replace those last 4 zeros with the speed sensor code (which I can look up). And hopefully that will allow me to connect with a speed sensor.
Then I will just need to find the characteristic UUID for the signal related to speed. Again, I can look this up. Hopefully this would then enable me to connect and get a readout from the speed signal from the sensor.
This would be a great start from which I can find out how to process this signal to actually read out speed and integrate into my app…