A couple of weeks back one of my friends suddenly went from Sevenoaks Kent to Manchester UK (200miles), stayed there about 5 hours then flipped back then back to Manchester (in same road) then back again. Needless to say Find Friends was wrong. Her location showed the same from several iOS devices so it wasn't a hardware issue. We all though she'd met someone with a helicopter. Obviously not the right app to track a partner to check on cheating !!