It is well known that the IM Client is a popular app for developers. As IM Clients go Spark has developed very well over the years. However, apps like PSI+ still have many attractive features not yet in Spark. Such as the selection of a system font for the current theme…or even the creation and use of a custom theme instead of the default two.
This is not a hard task, but one that would add considerable feature strength.
Also I wonder if there is any thought to using JavaFX to do this. That would lend a lot more flexibility to the design and implementation.