There is a kewl model named the Ultra Stick. The ARF version comes with two different sets of "ailerons". One set is full span ailerons, one for each side. The other set is 4 pieces. Two flaps and two ailerons (which obviously are half-span ones). You can build it with just the aileron set or build it with the set that gives you ailerons and flaps. The flaps turn the airplane into an entirely different THING.

It's interesting to use those flaps for takeoffs. The airplane already has the power to takeoff with a very short roll, but it still departs in a manner most airplanes depart. With the flaps deployed, the sucker sorta levitates.

Using flaps often causes the airplane to pitch. The computer radios can be setup to deal with that flap induced pitching. Otherwise, just hitting "some" flaps can cause the flyer piles of troubles..... or just piles (either piles... piles like in hemorrhoids... or piles like in wood pile).

The use of flaps is sort of an art. It often is tricky. In order to make it simpler and easier, flyers often setup their flaps on a 3 position switch.

Position 1 is up. Being on a switch, it's very comforting to know that with the switch in position 1, the flaps are exactly where they should be for up. It takes no special effort to flip the switch. And you can feel around with your finger without having to look, and tell easily and quickly that the switch is in position 1.

Position 2 is the takeoff setting. It's fairly simple to tune the flap deflection for the best setting for takeoff. And then it's dead simple to hit that exact deflection later on by just flicking the switch. Dials don't work so simply. Since takeoff setting is often halfway to the landing flap deflection, it's good to have an intermediate switch position. On your way down, you hit the switch to 2 and see how things are going on that approach.

Position 3 is the landing setting. It's simple.... etc..... Having just one deflection amount that repeats every time you hit the switch makes practicing landing with flaps a lot more effective. You really know that when the airplane "isn't landing the way it usually does" that it's either the way you're pushing the sticks or it's the wind/atmosphere that day. You know it's not because you didn't get the little knob turned too much or too little. And you know you got an exact amount of flaps (because the control is for a fixed deflection and it's on a switch that's going to give you exactly that deflection).