What event gets called on resuming a game on mobile?

So for my mobile game you can unlock a few players by being redirected to any of my social media accounts. I do this with a simple Application.OpenURL(). Thing is, I want to unlock the player after the player went into the browser (IOW when the player moves out of the game window).

But what event gets called when they go into the browser? OnApplicationPause ? and what gets called when they return from it?