Is the action bar crucial to an Android app?

Question

Currently I have a custom bar at the top of the page that has a header for the page and a back button to take the user to the previous page. I am also looking to include a button to access the settings page. On Android's website it says:

"the action bar, is one of the most important design elements in your app's activities, because it provides a visual structure and interactive elements that are familiar to users. Using the app bar makes your app consistent with other Android apps, allowing users to quickly understand how to operate your app and have a great experience."

Is the action bar actually crucial to the design of the UI or is making a custom bar viable? If making a custom bar is viable, under what circumstances is it viable?

Answer 1

As in most things in design if you are going to break the rule you should do it for a solid reason and to provide a better solution for your scenario.

This is context dependant, there are no general rules where breaking the paradigm is alright.

In your case it looks like the differences are in style. I don't think there is any problem. You can use a design (colors, font, etc.) that suits your brand identity, always within reasonable limits (be careful with the up button).