The metronome I developed myself, Bounce Metronome also has this feature, included in the "free taster" so this part of the program is totally free to use, no limitations.
It's for Windows, Linux (and soon to be released for Mac).
You tap with the backspace key and the dial auto-sets to the tempo of your taps.
However, it can't just listen to you and figure out the tempo that way, you have to tap at the tempo with the backspace key - and the other ones also require you to tap at tempo in some way (e.g. with mouse).
Don't know what there is by way of metronomes that can just listen to you and try to guess what the tempo is. Perhaps others here might have the answer.