Software is everywhere. The increasing requirement of sup- porting a wide variety of domains has rapidly increased the complexity of software systems, making them hard to main- tain and the training process harder for end-users, which in turn ultimately demanded the development of user-friendly application software with simple interfaces that makes them easy, especially for non-professional personnel, to employ, and interact with. However, due to the lack of source code access for third- party software and the lack of non-graphical interfaces such as web-services or RMI (Remote Method Invocation) access to application functionality, synchronization between het- erogeneous closed-box software interfaces and a user-friendly version of those interfaces has become a major challenge. In this paper, we design SINk1, a middleware that enables synchronization of multiple heterogeneous software applica- tions, using only graphical interface, without the need for source code access or access to the entire platform's con- trol. SINk helps with synchronization of closed-box industry software, where in fact the only possible way of communi- cation is through software interfaces. It leverages efficient client sever architecture, socket based protocol, adaptation to resolution changes, and parameter mapping mechanisms to transfer control events to ensure the real-time require- ments of synchronization among multiple interfaces are met. Our proof-of-concept evaluation shows there is in fact poten- tial usage of our middleware in a wide variety of domains.