A Health App for Post-Pandemic Years (HAPPY) for people with physiological and psychosocial distress during the post-pandemic era: Protocol for a randomized controlled trial oleh Justina Yat-Wa Liu, David Wai-Kwong Man, Frank Ho-Yin Lai, Teris Cheuk-Chi Cheung, Amy Ka-Po Cheung, Daphne Sze-Ki Cheung, Thomas Kup-Sze Choi, Gabriel Ching-Hang Fong, Rick Yiu-Cho Kwan, Simon Ching Lam, Vincent To-Yee Ng, Heung Wong, Lin Yang, David Ho-Keung Shum