As mobile devices are rapidly replacing desktop computers for a growing number of users, existing user interfaces often need to be ported from the desktop to a mobile device. In addition, successful user interfaces written for one mobile platform are commonly ported to other mobile platforms. Traditionally, porting user interfaces requires that their source code be reverse-engineered and translated, which is difficult and error-prone. In this paper, we present an approach that reverse-engineers user interfaces without having to analyze their source code. Specifically, our approach examines an interface's runtime representation by means of aspect-oriented programming (AOP). An aspect intercepts the program's control flow at the point when all the components of an interface are laid out on the screen, but before the interface is displayed. The aspect analyzes the interface's in-memory representation and extracts a platform-independent model that can then be used to generate equivalent interfaces for other devices and platforms. Our initial proof of concept ports Java Swing interfaces to Android. In this paper, we describe our approach, discuss its main technical challenges, and outline future research directions.

Abstract-To successfully compete in the software marketplace, modern mobile applications must run on multiple competing platforms, such as Android, iOS, and Windows Phone. Companies producing mobile applications spend substantial amounts of time, effort, and money to port applications across platforms. Creating individual program versions for different platforms further exacerbates the maintenance burden. This paper presents Cloud Twin, a novel approach to natively executing the functionality of a mobile application written for another platform. The functionality is accessed by means of dynamic cross-platform replay, in which the source application's execution in the cloud is mimicked natively on the target platform. The reference implementation of Cloud Twin natively emulates the behavior of Android applications on a Windows Phone. Specifically, Cloud Twin transmits, via web sockets, the UI actions performed on the Windows Phone to the cloud server, which then mimics the received actions on the Android emulator. The UI updates on the emulator are efficiently captured by means of Aspect Oriented Programming and sent back to be replayed on the Windows Phone. Our case studies with third-party applications indicate that the Cloud Twin approach can become a viable solution to the heterogeneity of the mobile application market.