In iOS 6, the built-in Maps application no longer provides public transportation information. Instead, it kicks you to 3rd party apps that provide that functionality. I'm currently running iOS 5, and won't update until I know there's a way to easily look up bus routes under iOS 6. How can I determine if there are 3rd party transit apps that cover my region?
I'm being deliberately vague on the region I'm living in, as I want a generic answer that will be useful to public transit users in all regions.