viewport markers

it would be useful to have the option of visually having reference of position x0, y0 of the viewport and layers, once unselected, the origin of some layers which happens to be the center in many cases is invisible and you can only guess about it center or selecting it again to check it position, i know some layers don’t have a center or origin but then again these still have coords and a little crossair would make things a little bit easier, and maybe drag/drop guides like GIMP or Inkscape have now that i remember =p