Android: what are the best practices for up/back buttons?

Question

I've been developing an android app. I'm a long-time android user and from my experience, I rarely (if never) use the up button provided at the top left of the activity and always use the back button and the bottom of the screen (either physical or on-screen).

I'm wondering if this is the case for most users? Is the back button sufficient or should I always provide an up button (iOS style) at the top left of the screen? Keep in mind that, in my app, the back and up buttons do essentially the same thing.

Answer 1

I'm aware that his question and answer are quite old, but dimshik seems to ignore the difference between 'back' navigation and 'up' navigation. The source he provides only talks about one of the navigation patterns you mention in your question.

'Back' navigation is used to move backward through the history of previously visited screens. It is provided by the Android device and should not be repeated in the UI.

'Up' navigation is used to navigation up the hierarchy of your app to parent screens. Your app should provide the necessary UI elements (often a arrow pointing to the left in the top left corner) for your users to navigate through the hierarchy of your app.

This page provides a much more complete answer to this question: https://developer.android.com/design/patterns/navigation.html

Answer 2

Back navigation is how users move backward through the history of screens they previously visited. All Android devices provide a Back button for this type of navigation, so your app should not add a Back button to the UI.

source: Providing Proper Back Navigation