Despite wowing WWDC attendees with its 3D "Flyover" mode for Apple Maps, the tech giant's alternative for Google Maps, some critics questioned whether building a first-party mapping application was wise considering Google is largely the go-to solution. A feature missing from Maps, transit directions, has caused petitions and numerous Web sites to criticize Apple.

A petition was started by Walk Score, a service which ranks cities according to how walkable it is, and encourages users to tweet or share over Facebook.

Apple doesn't seem to be integrating the service, relying on third-party apps to provide the functionality, which will be promoted from within Maps. Scott Forstall said during the Maps reveal at WWDC that the best transit apps are coming from iOS developers.

It means that in an age where less young people are driving and using public transport, third-party apps may arrive long after launch that show bus or train timetables. That might be enough time for people to switch to rival platforms, such as Google's Android.

The problem for Apple is that using Google Maps included directions worldwide, and it was reliable; Apple Maps uses TomTom and Yelp for its directions, which could be less comprehensive than Google. If so, users will ask why Apple switched and consequently may jump ship. There would also be the question of why Apple didn't build a dedicated turn-by-turn navigation app, to rival expensive App Store solutions such as TomTom, and continue using Google Maps.

Also, using Google Maps in a subway will display all of the times accurately to the minute. Undoubtedly, people who use the subway day-to-day will feel the difference if times suddenly aren't accurate, especially in bigger cities such as New York. On its latest episode of The Vergecast, The Verge's Editor-in-Chief Joshua Topolsky said using Android phones such as the Galaxy Nexus allows all of that information to be integrated across Google's services. Launching Maps in beta form like Siri, Apple's voice recognition technology, seems risky considering accurate directions will be needed from day one.

However, it should be noted transit directions weren't immediately available from launch in Google Maps: it arrived during June 2011. The difference is that Google had the time to develop new features as it was the only smartphone mapping service widely used.