Android Architecture Components (AAC) is a new collection of libraries that contains the lifecycle-aware components. It can solve problems with configuration changes, supports data persistence, reduces boilerplate code, helps to prevent memory leaks and simplifies async data loading into your UI. I can’t say that it brings absolutely new approaches for solving these issues, but, finally, we have a formal, single and official direction.
IntelliJ IDEA/Android Studio plugin that adds a 'Step Builder' action to the Generate menu (Alt+Insert) which generates a Builder class which follows the Step Builder pattern.