Download Notifu
Notifu is a tool that displays a yellow pop-up balloon in the system notification area, better known as the tray. It is free and open source.
Download
Click here to download a compiled version.
Click here to download zipped sources.
Installation
Notifu has no dependencies on anything. Just unzip the file somewhere and run it from there.
If you need a feature that Notifu doesn't provide, . What's missing is easy to add. I just stopped when I had everything I needed.
If you haven't done so already, you can look at the documentation or read about the implementation
