The big difference is Android uses a standard back button for all applications. This leads Android users to end up mashing a lot of buttons at random, to try and get what they want - it's actually quite a bad UI, and it was just translated from the web clumsily.
On iPhone, each app has its own navigation method, based on the requirements of the app. The main nav options for an iPhone app are:
* a navigation bar that stacks a series of views, with a back button.
* a tab bar which gives a 4-5 ever-present options on bottom
* a single view with buttons for menus
Even when you implement a nav bar for an app, which is similar to Android, it's much better, because the stack of views is deterministic. You can never tell what the Back button will do on an Android app.