As many men my age the weight is starting to escalate beyond what is good for once health. To stop this and to be able to measure my progress in doing so. I bought what I thought was a resistive body-fat measure device. However upon first use at the coffee table together with a few colleagues it soon revealed itself that the little device has all the properties and apparent features of being a device that measures the fat in your body by sending electricity through it. You enter data about yourself such as age, weight, sex and length, then you hold your thumbs on the metallic plates and a progress bar appears, after a while you get your bodyfat in %. So I tried to trick it after we checked our fattnes, me and my colleagues, by wetting my thumbs thus removing resistance. Same % as a result. Then the others tried it, same % as me (on my settings). But when shorting the path it did say error (almost half-clever) . You can let go as soon as the progressbar starts though.
I was fooled, thats the downside.
The upside is that the device has two body contacts, a battery compartment (for a standard CR battery), a pretty decent screen and a speaker. So perhaps you could put something that makes noise inside it that uses body contacts to make the sound. That could be awesome, using it for what it was intended for isn’t.