You will find very few icons theme where creator work really hard to pencil icons for your desktop to make elegant. Ubo icons a great icons set drawn with ballpoint pen, then scanned and colored in GIMP. Isn't it feels great to have such hand-crafted icons specially for your desktop, the icons are not glamorous, nor glossy finish but give a unique look to your desktop.
The icons theme is in active development "work in progress", creator is trying to add as much as he can and you will see more icons added to this icon theme. I urge you to visit his icon page and show some love, doesn't matter you use icons or not, whether you like this icon set or not. These icons are compatible with most of the desktop environments including Gnome, KDE, Unity, Cinnamon, Mate, Xfce, Lxde, and so on. If you find any missing icon or problem with this icon set then report it to creator and it will get fixed soon.
The icons theme is in active development "work in progress", creator is trying to add as much as he can and you will see more icons added to this icon theme. I urge you to visit his icon page and show some love, doesn't matter you use icons or not, whether you like this icon set or not. These icons are compatible with most of the desktop environments including Gnome, KDE, Unity, Cinnamon, Mate, Xfce, Lxde, and so on. If you find any missing icon or problem with this icon set then report it to creator and it will get fixed soon.