Track the balance of an xPub (or multiple xPubs!!) and graph the connections between the different addresses involved. Try it out with this example xPub:

Current implementation: It searches the '0' key space for receiving addresses with a gap limit of 20, and then joins together the change address "1" keyspace. Address limit is at 50 while we are testing the load of this feature.

Give it a try if you'd like and let me know if it works well for you. Thanks