USB on the surface may seem simple. Under the hood is a convoluted system of different shapes, multiple versions, and a higher-end standard that runs parallel to USB. Unfortunately, USB is not as simple as it appears. So, here is everything you need to know.
Markup tools was a feature added in iOS 10 that allowed users to use basic editing tools for images. They started out being very limited but have now expanded to many other places around your iOS device. The places it can get use the most are in photos when taking screenshots and saving PDFs in Safari.