Can We Have a symmetry option

In the meantime a workaround is mapping a tile then placing a mirrored copy of it next to the original tile.

oh and maybe a dimensions thing like Photoshop so its easier to find the center of a tile or image.  

for the dimensions thing, i draw myself a center point in a tile and used that as a seperate temporary "helper" layer, so you always have a dot in the center (or whereever you need a reference point)