I came across this Instructable a while back, and before I could make it, my neighbor (Fatman) built me one.
http://www.instructables.com/id/10-Smartphone-to-digital-microscope-conversion/These are some of the photos I've taken with the setup.
Pumpkin cell (added yellow filter):
Pumpkin cell (no filter):
Tilia cell:
Onion skin:
Pine needle:
Bryopsis:
Amphipod:
Since I can't leave well-enough alone, I've been tweaking the setup. I'm trying to break 400x with various lenses. I'm also adding a yellow, blue, green, and red filter. We'll see how the mods go.....