Call a phone number from app (or text)?
Google Now on Tap
on Marshmallow does something similar but not perfectly

Long pressing the Home brings up the Google Now on Tap with various options , one of them being calling the number listed ( others being- text, share and add contact). The number gets pasted on the  telephone app without any user intervention. One can directly call from there


This is from a resturant search using an app. It works well in this case





This is from a random telephone directory search on mobile browser (details blacked out for obvious reasons). Here, it picks up only the first number, so this option is a hit and miss , if there are several numbers in the image