@NullPointer - Your best bet is to do the research yourself. Find the pieces of the watch (should be listed somewhere on the place selling it), and there may be a limited number of OSes capable of running on it. If you have an ARM based watch then the list is huge, but pretty much all of them is just Linux plus some extras. If the watch is really cheap you can even open it (since you're not afraid of breaking it) and read the models of the chips.

(really, simply googling the text on a chip often gives decent info)

@grochmal thanks man. I'm working on it

@grochmal I use both

@Gilles - I need to admit that I too use emacs sometimes. M-x set-input-method is much better than the one in vim