I agree… the Accu-tuner is an overkill for the harp. I just would find it interesting if a working accomplished piano technician could tell us how it would work on the harp.
I have no real opinions about the other tuners… but… it you have a smart phone such as an iPhone or one of the others, there are several apps with tuners on them. Tony, do you know what they are called? I remember running across different tuners at the iPhone app store, some were for free and some were a nominal cost….