Updating this old thread with more links.
I have the Anatek Corp "Blue Ring Tester" and it works well in checking flybacks. It is sold as fully assembled or as a "build-it-yourself" kit with all the parts included (except for a 9 volt battery of course). I like this tester.

Manufacturer's website:
http://shop.anatekcorp.com/products/component-analyzers/blue-ring-tester-kit/Current version of the fully assembled model User's Manual:
http://shop.anatekcorp.com/clientuploads/directory/products/Blue%20RT%20user%20manual_Oct%202014.pdfBe advised if you have/encounter an early production model, there is a problem with the calibration/sensitivity showing most or all flybacks as being bad when in fact they are good. The problem was traced to an incorrect resistor installed on the board. Here is what Anatek says:
"NOTE: A late design change made resistor R7 510 ohms (green-brown-brown) instead of the 2.2 Kohms shown
on the pcb silkscreen. This change makes the tester more sensitive when used on low impedance
components such as SMPS transformers and deflection yoke horizontal coils and flybacks."
Mine was an early model and the resistor change fixed mine right up. It works correctly now.
Helpful videos: