BlueWho informs and notifies when a new bluetooth device is discovered. Detection can be requested by the user or automatically continuous until it's stopped. A visible and audible notification can be triggered whenever a new device is detected.

SciDAVis is a free interactive application aimed at data analysis and publication-quality plotting. It combines a shallow learning curve and an intuitive, easy-to-use graphical user interface with powerful features such as scriptability and extensibility.

Zyne is a modular synthesizer which comes with more than 10 builtin modules implementing different kind of synthesis engines and provides a simple API to create your own custom modules.

Tucnak is a VHF/UHF/SHF logging program for hamradio contests. It supports multi bands, free input, networking, voice and CW keyer, WWL database and much more.

This is the panel provided by the Xfce4 desktop project. If you want a multi-functional panel that can even handle plugins and the like, xfce4-panel might be worth a try.

LXTerminal is a VTE-based terminal emulator for the Lightweight X11 Desktop Environment (LXDE).