Kontrast is a color contrast checker and tells you if your color combinations are distinct enough to be readable and accessible.
Akira
Akira is a native Linux Design application built in Vala and GTK. Akira focuses on offering a modern and fast approach to UI and UX Design, mainly targeting web designers and graphic designers. The main goal is to offer a valid and professional solution for designers who want to use Linux as their main OS.
Pencil
The Pencil Project’s unique mission is to build a free and opensource tool for making diagrams and GUI prototyping that everyone can use.
App Icon Preview
Tool for designing applications icons.
Contrast
Checks whether the contrast between two colors meet the WCAG requirements.
GColor
Gcolor3 enables you to pick the color from any pixel on your screen.