I think a welcomed addition to the friends profile across all apps would be the ability to see a friend's daily step count. This would be useful when "chasing" a friend down. 
Other user data such as, distance, active minutes, pictures and other information that person has set to share with friends would be nice as well.
Idealy the user would be able to slide through previous days like you can on your personal dashboard view
Moderator Edit: Updated Subject for Clarity/ Edited Labels
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