Perhaps. The virus he's using is hardly an original, the only thing he's done to it is allow him to read it. And even then, as long as you update your phone regularly, it'll get rid of the virus be planted before since it only works on certain versions of your app. If he wants to keep track of you constantly, he has to constantly update the virus to the app, though he only needs to use it once to see where your scroll as been.
Now if you mean researching Sapphire's family is going to blow up in his face, I'm not too worried. If you think I should be worried that someone is going to dig through Gren's background, by all means, go for it. I'm honestly quite surprised no one else has. It's not exactly hard; Gren's father keeps no secret that his son used to run with the White Fang. Kinda a sore point between the two. Much of Gren's dark history could easily be traced simply by knowing some of what the White Fang did, some of their key members, and matching that description up to Gren. That is to say, big robot looking fellow with a minigun, killing lots of people. Granted, nowadays the White Fang have more people like that, and Gren just happens to fit that description, but it's no coincidence. You look into his past records about the schools he attends, then look into those schools, and you'd find that Gren never went to them. Unlike Sapphire, Gren's past is hardly as secretive. And that's mostly because his past, until it catches up to him, doesn't bother him anymore.