PlayStation 4 won't show Trophies when you're offline, still requires sync - Polygon
If you've fulfilled PS4 trophy requirements on PC or Xbox, you'll auto- unlock the platinum trophy upon CS-ing your characters onto PS4. : r/DestinyTheGame
This secret PS4 feature helps you unlock trophies - PlayStation Universe
PS4 Trophy Modding by ThisIsMrNameless, RTM Guide by Hydrogen | PSXHAX - PSXHACKS
PS4 - PS4 Trophy Unlocker v1.0 by The Darkprogramer | PSX-Place
The fastest PS4 Trophies: Earn 14 Platinums in 12 hours | GamesRadar+