Maybe 5y ago I bought a USB otoscope. Less than $20. 6 LEDs for lighting, but fixed focal length of about 3/4". So if what you are looking at is closer or farther than 3/4", it is out of focus.
The built-in Windows "camera" app makes it so it is accessed just like any camera. No special app to get. Using a computer gives you a huge display, plus the ability to record images. But not very good as an otoscope.
I mention this cuz these cheap endoscopes have gotten lots better. USB or USB-C plugs now available. Adjustable lighting. Wireless transmission. Wider viewing angle. Still under $20 in the US. I may get another to try it out.