The Effects of MyChoices and LYNX Mobile Apps on HIV Testing and Pre-Exposure Prophylaxis Use by Young US Sexual Minority Men: Results From a National Randomized Controlled Trial - Katie B Biello; Kenneth H Mayer; Hyman Scott; Pablo K Valente; Jonathan Hill-Rorie; Susan Buchbinder; Lucinda Ackah-Toffey; Patrick S Sullivan; Lisa Hightow-Weidman; Albert Y Liu (JMIR Public Health and Surveillance)