Doesn't really matter what you use as long as you aren't utilizing any protected health information (hpi). If you are using information that can identify a patient then you need to be using an approved encrypted device. Generally providers tend to avoid utilizing that type of information just out of habit.

You don't really discuss patient information or their care with anyone over mobile devices. If you need input from someone directly concerning patient care you tend to do it over EMR so your colleagues have context about who you're talking about.