3ribal

>"developed anything in messenger even today"

I have developed several, your statement is misleading. Messenger user profile API gives,

first_name, last_name, profile_pic, locale, timezone (non precise), gender, is_payment_enabled, last_ad_referral,

Which IMO is much safer than using direct Facebook Graph API. My point being Messenger apps are in-fact better than apps which uses Facebook login when it comes to privacy i.e if you have to use Facebook platform.