When Apple replaced Google Maps with its own app on iOS 6, it left an opening for one major feature: mapping out public transit directions. While Google hurries to build a replacement app for iOS, Apple has leaned on existing services, letting users find and download local apps directly from Maps. And unsurprisingly, app developers are reporting a windfall from the new system. CNET reports that it's been a "crazy week" for people like Sam Vermette, who built trip planning app Transit. Vermette says he's seen a spike in app downloads and subscriptions since iOS 6 was released.

Embark co-founder David Hodge, likewise, says downloads of his company's apps rose dramatically — 1.3 million trips have been planned in the week since iOS 6 was released, a significant portion of the 40 million total trips Embark has served up since 2008. These transit apps, along with others like iTrans, have been running for years, but they're not the only ones trying to benefit from the change. GPS provider Garmin recently released updates to its navigation apps, adding transit directions and Street View-style photos. While users seem to be finding plenty of apps through Apple now, it's less clear how many will stick with them if Google brings its own Maps system back to iOS.

Update: Since publishing, we've been able to talk to Adam Ernst of iTrans, another major player in US transit apps. While he didn't give specific numbers, Ernst agrees that there's "definitely a big reaction" to the change, and that downloads have spiked since iOS 6 was released.