I have faced the problem of writing the very same feature/screen for many apps. It seems quite obvious. Designing the interface, using some inheritance can easily make the day.
However there are some small and ridiculous issues:
- watch out for helper or utility methods, constants! - try to use a unified set of helper classes for some task, so you can easily share or in worse case copy them.
- check hidden requirements! if the "same" feature in two areas looks 90% similar- it will give you a hard time to implement for both cases.
- C-based lets you build a common code folder to include or even a library
- Java based projects will give you a hard imeas package identifiers will contain app specific parts. Consider library based approach.