Very simple graphic design

I require 4 sets of images for an ios app currently in development. I would create them myself but would prefer to outsource this graphic design, with the possibility of further outsourcing to come. - The images will be largely identical to the example images (ie. 4 images, looking basically the same) - The images will be provided in both retina and non-retina size - The images will be provided named and formatted in an appropriate fashion for import into xcode - The images will measure 40 points by 40 points - A 400 pixel PSD or other high resolution source image will also be supplied. The images required are as follows: - 'empty box' - An empty square - 'half filled box' - the above with a diagonal, bottom left to top right, line across and filled in the superior section - 'filled box' - the above, completely solid - 'checked box' - the above with a green checkmark superimposed on it example images are provided below Generic applications will be ignored; please indicate that you are aware of xcode requirements for images.