A Personal Finance Manager for humans
LabPlot is a KDE-application for interactive graphing and analysis of scientific data. LabPlot provides an easy way to create, manage and edit plots and to perform data analysis.
RKWard is an easy to use and easily extensible IDE/GUI for R.
Umbrello UML Modeller is a Unified Modelling Language (UML) diagram program based on KDE Technology. UML allows you to create diagrams of software and other systems in a standard format to document or design the structure of your programs.