Meet the iMicro Q2p: a tiny 800x polarizing microscope for your smartphone that fits on your finger. It has a resolution of down to 1 micron and comes with a focusing stand to gives you better control. It should work with most smartphones on the market.
You can use this microscope to explore crystals, insects, rocks, and everything in between. It weighs only 0.5g, measuring 3.2mm in thickness. Expected to ship in April.