Swipe menu is a circular menu that shows up when you touch nodes, connections and the background.
If you release it, the menu will disappear with a buzzing sound.
To activate an option, swipe through it without releasing the touch. It will allow you to enter submenu, perform an action or do some other thing using the same touch that you used to open the menu.
Slight movements of the finger cause the menu to follow it. Major finger movements allow you to lock-on particular option and check its description.
When your finger will approach edge of the screen, the menu will scroll in the opposite direction. This movement is quite fast and may cause unintentional activation of an option. To avoid it, after opening a menu near the edge of the screen, gently move your finger away of the edge, following radial menu scrolling. You can still move the menu around using slight finger movement around center of the menu.
It is worth remembering that Dessin is a multitouch application - you can open several radial menus simultaneusly. It makes things significantly faster when you want to create several labels or connections.