libunique-dev binary package in Ubuntu Xenial amd64

 Unique is a library for writing single instance application.
 If you launch a single instance application twice, the second
 instance will either just quit or will send a message to the
 running instance.
 .
 Unique makes it easy to write this kind of applications, by
 providing a base class, taking care of all the IPC machinery
 needed to send messages to a running instance, and also handling
 the startup notification side.
 .
 This package contains the headers and development libraries needed to
 build applications using the Unique library

Source package