The airport bus transfer take you back and forward from Östersund to Åre Östersund Airport. The bus transfer depart according to all flights to/from Stockholm Arlanda/Bromma.
For information regarding timetable for the airport bus, please see http://www.nettbuss.se/tidtabeller/flygbuss-are-ostersund-airport.
From the airport to Östersund: the bus transfer departs about 15 minutes after the flight arrives, bus stop just outside the entrance. It takes about 15 minutes to Östersund city. If cancelled flight departure=cancelled airport bus transfer.
Note: The airport bus transfer only traffic Östersund, for Åre see www.flygtaxi.se/en