This is a Coleus Blumei plant, Plectranthus scutellarioides or formerly called Solenostemon. Many complicated names, but to me this particular one is known as China Rose. They are so easy to grow and come in the most extreme colors and patterns, this variety is one of the most common and most spectacular. I currently have a collection of maby 80 known hybrids, and another 30 or so that I've grown myself from the seeds from my plants. In the summertime there will be even more, since I live in the north I can only have them outdoors a few months every year. This has to be one of the most purple things alive!