I used services from Robert Kullberg from Fastighetsbyrån to buy a new apartment and sell the old one.
Obviously I speak English and I'm new to Sweden.
Through the whole process he helped me by describing the rules as well as how to make a fair deal. I got a very good service with a high quality. My dealer was always accessible and did his best to give us a smooth and easy experience. I highly recommend him for buying or selling apartments.