Smartphone application for women with gestational diabetes mellitus: a study protocol for a multicentre randomised controlled trial Borgen, Iren, Garnweidner-Holme, Lisa, Flem Jacobsen, Anne, Bjerkan, Kirsti, Fayyad, Seraj, Joranger, Pål, Lilleengen, Anne Marie, Mosdøl, Annhild, Noll, Josef, Småstuen, Milada Cvancarova, Terragni, Laura, Torheim, Liv Elin, Lukasse, Mirjam (2017)