A friend used to have one with a sort of slider; it was still though a digital touch interface but had enough steps to make it feel continuous. Never wrote down

A friend used to have one with a sort of slider; it was still though a digital touch interface but had enough steps to make it feel continuous. Never wrote down what it was, and never saw one since. I myselr used to have one that would go in 200W steps, that was also pretty great. Also never saw that on another model.