Often its is said that Google creates the most usable of Apps and I constantly try to find a reason behind it. A simple display on of information on their Maps App on iPhone (or Android, since I use both) presents the user with a lot of Data. A restaurants name and address and phone number for instance. But from here on its all downhill, the Map app just allows you to see that information, but if you have to make a call to that number, you better get ready with your Notes App to write it down or memorise it and then type it back in where its needed.
The right way to do it on a Phone App is to just give a Call Button that takes the phone number and dials it. General assumption is, if there is a number displayed on my phone whether in email or any app, in all probability I would like to save it or dial it. The actual number really does not matter any more since we are not dealing with paper and pencil here.