Let me offer a different view. Two years ago I purchased Peterson's Strobosoft software for my PC. The deluxe version was $100 or so and offers a very nice tap tuning capability. I started recording what my tap tones were on my tops, backs and the body resonance of the assembled body. I do not tune to specific notes, I just record the data. Like deflection testing, this is information. The idea is, if you build a killer instrument and you have kept records of the tap tones, as well as the other details, you may have some basis for repeating the build. Most of how I build is very intuitive, so I enjoy being able to go back over the data and look for trends. And, by the way, some months after buying the software for my PC, I bought the istrobosoft tuning application for my iphone. It is sensitive enough to tap tune and checking it against the PC shows it to be within a couple of cents.
Brad