Presence detection: user of device?

What is the (best) way to track and automate presence detection. Is it better to use the User of the Device? I have a user (HA-Main_User) that is logged in to my laptop webinterface and logged into the HA app on my iPhone (iPhone_User). When looking in the device history the tracking of person.ha_main_user and the mobile app device iphone_user seem to be (almost) the same.

Is there a prefered/better/only way what to use in automation for presence/zone detection? User or Mobile App