Great place to stay when visiting Oslo. We were a family of four and found Kristine's place an ideal place to stay. We were unlucky that work was being done on the metro line however the number 70 bus was great and took us all the way to the centre in around 20 mins( National Theatre being the last stop). Tickets can be booked on the app before boarding the bus.
The apartment has everything you need including a washing machine. The place was very clean and new. The kitchen had everything we needed to prepare dinner and lunches for the next day. Definity would recommend if you do not mind being a little bit out from the city centre.