This simple addon placed in object section in object mode, allows after performing a selection to flip the mesh immediately, leaving it in the exact same spot. Additionaly smoothing and flipping of normals is performed automatically (necessary after flipping on X -1.000). Calculation is performed to place the object exactly where it was originally but flipped. This is very important to add variety when you work for studios and big companies they may ask you to perform some variation on the finished models. The addon is very performant. Object flip is accessible also through the right click context menu.