Most small domestic laundry spin dryers appear to have little control over their spin speed. Often it is usually on or off which means that the motor attempts to spin the drum up to full speed straight away.
Often if the dryer is loaded with absorbent items such as towels which by their nature can hold a _lot_ of water, the drum is unbalanced and the dryer either starts to dance around the room spilling water all over the floor or the drum bounces off the inside of the dryer.
What appears to be needed is a more gradual spin up of the drum so as to allow the worst of the absorbed water to drain off the towels etc. first before increasing the motor speed.
What would be good as well as having some form of programmable speed control, would be some form of a vibration/knock sensor that would automatically keep the motor RPMs reduced if the load was still unbalanced.
A bonus feature might be a drain sensor to detect when no more water was coming off the laundry and to remove power to the motor and alert the user that the dryer is ready to be emptied.