If you want to know the function of each toolbar button, press or
button on the right.
Tap button, window with object library appears,
tap object to add it to the project.
Tap to select the object.
Use small white squares to resize and green square to rotate the object.
Basic project size is set as width and height in Project Properties . There is a fixed space around the project defined there as well.
Switch into Wall Editor to add more walls to make a more complex shape of the room, or add more rooms.
Each wall lies between two control points. Neighboring walls share one control point. It is crucial to connect walls like this, and not to have duplicate control points. To check this, each control point changes color according to number of walls using it.
Each wall can have different thickness, and is aligned relative to the line between control points. Both is set in wall properties in Wall Editor (right click in desktop mode, or tap wall in touch mode).
In most cases, Room Arranger is used to design rooms, apartments or houses. The example below shows quite a detailed project of one house floor. Things are much easier when you have just one room to do...
Start with empty project
Add walls in Wall editor
Add furniture, define colors
View in 3D (top view selected)