The iPhone is not charging above 80% or taking hours to up from 80. Does anyone know what’s happening?

I was using the Fing app and noticed it could identify my iPhone model, iOS version, and the brand of my other devices, even though Apple restricted access to MAC addresses starting with iOS 7. I’m curious about how Fing detects this information on iOS devices. I couldn’t find any details about this online.

Thinking about buying an android, but was told malware device is able to enter. IOS is apparently not possible to install malware.

The logo of the app is not available after I download certain apps from the App Store on an iPhone. What should I do?