?url_ver=Z39.88-2004&rft_id=10.2196%2F21085&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.aulast=Stoyanov&rft.aufirst=Stoyan+R.&rft.au=Stoyanov%2C+Stoyan+R.&rft.date=1+April+2021&rft.issue=4&rft.volume=9&rft.atitle=Development+of+the+niggle+app+for+supporting+young+people+on+their+dynamic+journey+to+well-being%3A+Co-design+and+qualitative+research+study&rft.issn=2291-5222&rft.title=JMIR+mHealth+and+uHealth&rft.genre=article