I have found that my iPad takes much better pictures about 4-5 inches away from a coin. It can't focus any closer. So I just pinch-zoom from that point, and it does okay. Indirect sunlight on a bright day also seems to illuminate better than LED.
For tiny stuff, I bought a cheap $8 magnifier on
Amazon, and it does alright. I filter the LED light with a ply of tissue fastened with a bread twisty tie.