After seeing this article in Make Magazine, I ordered some lenses and got to work.
The setup was very similar, however instead of using a flashlight, I installed a bright LED soldered to a USB cable, so you can easily power it.
You essentially have a platform on which the lenses are mounted and where you rest your smartphone and then you have a transparent specimen holder of adjustable height and a backlight. Incredibly simple setup.
Despite the simplicity, the results are impressive. It does work, as the images below demonstrate. I looked at some leaves, a bug and onion peel.