Start on Android by Google - Developer program to optimize your app before you launch
Pixelmator - Pixelmator is an image-editing application for Mac and iPad.
Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Canva - Canva is a graphic-design platform with a drag-and-drop interface to create print or visual content while providing templates, images, and fonts. Canva makes graphic design more straightforward and accessible regardless of skill level.
adapta-gtk-theme - An adaptive Gtk+ theme based on Material Design Guidelines - adapta-project/adapta-gtk-theme
zipBoard - ZipBoard is a web-based visual bug tracking & issue tracking tool that helps developers, testers and project managers collaborate during website and elearning development.