SimplePlanes is fantastic! And, I realize that part of its brilliance is, well, its simplicity. To me, though, the ability to manipulate drag on a plane's airfoils is as fundamental of a control surface as ailerons, elevators, and rudders. I have seen flaps mentioned in combination with other feature requests, but I just wanted to get a singular request out there. To me, landing is the most challenging and exciting part of flying and a true test of mastery over a given airframe. Flaps are an essential part of this stage of flight. It would be great to add flaps in designer mode, lock it in at preset settings, and view corresponding changes to CoL and drag points at each setting.