On Tuesday one of my dojo-mates showed up with a small tablet computer running an Android application called YumiReco that let her track hits/misses and other information. It seemed pretty well done. One feature is that you can graph your hitting percentage, and see the waves of ups and downs over time. There are still some rough edges, but you can send feedback to the author for improvements.
The interface I saw was all Japanese, so I don’t know if it can be switched to other languages. If not, maybe someone could contribute a translation of the necessary English text? But the hit/miss recording is done just by touch, so it should be usable regardless. Anyway I thought some people might be interested. Maybe if people know of similar software they could post a comment?