If your system has simple assets defined, adding them to the system in the Gully SMART apps is as simple as adding any other asset. They do not require any information over and above their location, and you can only log the predefined action against them.
From the map screen, tap the + button.

Tap the required simple asset from the list.

Drag the target to the desired location, and tap OK.

Tap Yes to save the asset to the system.

The asset has been added to the system, and the default action recorded.