"Jettestown" appears on this 1827 map:
http://maps.nls.uk/view/74400163I think I have found Balgay farm.
Looking at google maps, when travelling SW on the A90 out of Inchture, there is a road on the left. It looks like the first road past the roundabouts, however it is just a lane - you can approach Balgay farm via google street view from the other road. There are a couple of other farm houses along the road but I believe Balgay is the largest and has the most outbuildings and is located near where the road bends at an angle.
I estimate Jo(e)tti(e)stown was located two thirds of the way between Inchture and Balgay as the crow flies. Sadly there is no evidence of any farms around that area. There is a river in the vicinity and one would assume the farm buildings would have been nearby.
However if you follow the stream north from Balgay Farm, there is a building where this joins with another stream. I cannot get close enough to see any detail, so do not know if this may once have been a dwelling. I may be wrong but I think this may be in slightly the wrong place to be the remains of Jettistown (it may be a byre or similar).