Firstly, how did it do this precisely? Did it uplink/hack into satellite surveillance tech? If so, it would get static pictures taken every so often in certain increments of time, or pictures it can take right then as a query. However, it would then have to devote a massively fine tuned search engine to essenitally go "Where's Waldo?" and pick Molly out among the populace of NYC on the street (assuming she is on the street when it searches). The Leapfrog is most definitely capable of ultra-tech like that I would think, because Chase's parents were absolute genius inventers. Now, I'm not an expert in satellite tech, but I'm guessing that at least some satellites are capable of going to zoom video feed if queried to do so, so once she is found in a static picture, it can then find a video feed and zoom in and track her movements that way. That of course raises two very important issues, however.
1) When she enters into any building, she is suddenly not visible and thus not trackable. It only has the last known coordinates, and if it doesn't see her exit it doesn't know where she went to continue tracking. And there is a much more important Reason 2 for potential plot purposes:
2) There are likely a VERY VERY limited number of such advanced satellites. And my money's on the idea that they are likely in the possession of the CIA and more importantly, SHIELD.
I'm willing to believe the Leapfrog is damn good at what it does, but at the same time, SHIELD is notoriously Better Than You. I don't care who You are. Therefor, if it piggybacked on a SHIELD operated or used satellite, I'm willing to bet they at least noticed, even if they didn't or couldn't do anything about it. And you guys all thought attracting the Avengers and Captain America's attention was bad...
If this were the Ultimate Universe, I would so offer to NPC SHIELD characters and Nick Fury if this latter idea sparked interest. However, I am woefully unfamiliar with the canon 616 Nick Fury unfortunately aside from a brief cameo in a MAX Punisher trade.
Now, although I have discussed the Satellite feed idea at length, the other idea that is moderately feasible but not precisely canon or mentioned is that that Molly was tagged with a tracer by the Leapfrog at some point. That is the other way I can think of for a moving blip. If it did this to her, did it do it to everyone else? If not, why just her? If so, what about Nico? Which leads me to my next point that Karolina so nicely brought up...
What about Nico?
If it can trace Molly, and we say that it can do this in spite of buildings obscuring vision of an eye in the sky, (which of course is only one option at this point and requires a tracer) can it do this of Nico? Or is there an intervening reason? If there is an intervening reason, like Master Kenneth having blocking tech or magic, then that offers another potential idea for finding Nico in addition to the alien metal of the bracelet (Kar is genius!) if there is tech to trace that. If Molly does get there first, her blip will disappear. They'll have a record of where it disappeared and thus a target to aim for in finding Nico whether Molly succeeds in rescuing her or not!
As you can see, there is much potential for future RP and ramifications with this tracking tech. Thoughts, anyone?