Here is the project file screen. This screen comes up first when you open the app. You can work on an existing project or start a new one.
Here is the UI for ArtBoard. The tool panel is on the left side and the symmetry tools, layers, and import/export menu are in the upper right hand corner. Save is triggered by hitting the back button.
The color picker has two modes HSB or RGB color. You can use the wheel or the sliders to pick your color.