I wonder, if Google's Material Design is applied on Stack Exchange app, it would be great. Isn't it?
While I agree that apps look much better when they're designed to meet the design guidelines for the host operating system (e.g. Material Design on Android), there are lots of bugs and feature requests which are much more important than changing the design:
- Allow us to vote to delete from the Android app
- Add chat rooms for Android app
- Add review queues to Android app
- The app forgets that I voted when I scroll the question
...and many more.
I think that it is important that bugs which harm the usability of an application and highly requested features are implemented before the design is updated, when the current design is working quite nicely.