Yes, you read the title correctly! $5 for a clip on smartphone microscope attachment. And for $5, it even includes the three watch batteries needed to power the built in LED.
The packaging claims thirty times magnification. I didn’t have the time to confirm that.
What I can confirm is that the attachment is worth buying for use with a surplus smartphone you have lying around at home. Your students will appreciate the chance to explore their classroom or the school playground at high magnification!