I thought Apple's Find my Friends app had a built-in 'fuzz my location by...' setting where you could do 0, 0.1, 0.2, 0.5 etc. miles. I can't find it now though and am possibly therefore misremembering it as something else.
Either way, it's trivial to take a lat and long and randomise a +/- on each value, or alternatively if you want a ciruclar error randomise a magnitude and angle and resolve the shift to lat and long.
Either way, it's trivial to take a lat and long and randomise a +/- on each value, or alternatively if you want a ciruclar error randomise a magnitude and angle and resolve the shift to lat and long.