This will be a 24-week prospective cohort study that will incorporate user base data of WayBetter Inc.'s app, "WayBetter," to examine user mHealth app engagement. Our study sample will consist of approximately 1000 adult users (aged ≥18 years old), who are new app users. As users may have varying registration dates, the data collected will only include the first 24 weeks of an individual's interaction with the platform. To be included, study participants must be enrolled (within five days) and/or recently completed their seven-day free trial on the WayBetter app. Participants who are not proficient in the English language will be excluded. Prior to gaining access to the app, participants must provide informed electronic consent allowing aggregated data (without identifiers) to be shared with third parties, as a part of WayBetter's privacy policy (https://waybetter.com/privacy).

WayBetter is a wellness lifestyle mHealth app available to anyone who wants to improve their overall well-being. All users are asked to accept the company's privacy policy and are prompted to fill out personal data including (but not limited to) \[email address, weight\] when creating an account. All users are given a one-week free trial as well as $10 USD to use as a deposit towards any WayBetter app game, courtesy of WayBetter Inc. Users can complete any of the games they signed up for during their free trial, even if they decide not to continue to their membership. To continue to participate in games, users must subscribe to a six-month membership ($69 USD total). In general, users can join up to ten games at a time. The app has a game directory ("explore" tab) that includes 60+ games each week in three categories: fitness, nutrition, and mindset. New games start on Mondays, Wednesdays, and Fridays. Each game lasts between 1-4 weeks and requires players to achieve a specific behavioral goal (e.g., 5K Steps Per Day requires that they walk at least 5,000 steps per day on at least four days per week for two weeks). Another example of a game would be, "Healthy Hacks" which requires participants to focus on portion control and finding healthier alternatives to snacks on at least two days during the week. Or "Read A Book" which encourages participants to unwind with a 15-minute reading session on at least four days per week for two weeks. Upon joining a game, players have an option to make a deposit, called a "financial commitment" of $10-30, depending on the game. Multiple methods are used to validate goal achievement. Some games require players to verify their physical activity data by connecting their WayBetter app account (i.e., syncing) to a wearable device or step tracking app. Other games require participants to verify their behavior by submitting photos (e.g., photo from their wearable device or step tracking app showing that they met the game's daily step goal; photo of meals they ate). Each game also has a social feed, where users can view each other's posts and photo submissions and share anything related to their fitness journey (e.g., progress, inspiration, something they are proud of). All players who achieve the game's goal are declared "winners." Winners who made deposits are rewarded by splitting the total pot of deposits evenly, such that they earn back their original deposit plus addition profit, dependent on how many users 'lost'. The app incorporates an additional gamification aspect by introducing levels; players are required to win 3 games to advance a level (one from each category; they can choose any games they want).

WayBetter will send out a recruitment email to WayBetter users five days after they enter into a seven-day free trial. A reminder email will be sent to users seven day after the initial recruitment email was sent (day 12 of account creation) to prompt survey completion. A free trial sign-up for the WayBetter app can occur in two ways. First, a user completing the WayBetter "quiz" (a survey marketed via social media platforms and on the WayBetter website; Group A, "quiz taker"), can sign up at the end of the survey to begin their 'personalized journey' to healthy living (based on their survey answers) by starting their free seven-day trial. The user would then place their credit card information to secure their 'personalized journey', create an account, and begin their seven-day free trial. The second method to begin a free trial is when a user has already downloaded the app (Group B, "organic" users), created an account, and then is prompted by the app to provide their credit card information to sign up for a seven-day free trial. In this recruitment email, participants will be invited to complete a study survey via the RedCAP link provided. Participants will be prompted to complete the survey within five days to create urgency to complete the quiz. We want new users to complete the survey as soon as possible from the time they completed the free trial, so that they do not become an experienced user, which has the potential to affect the way they answer some of the survey questions. After clicking on the link, participants will first be prompted to read the study LOI. Thereafter, participants will be asked to complete the survey which will aim to collect information about individual-level socio-demographics (i.e., household income, rural or urban living status, gender, age, race, and ethnicity), previous health behaviours (i.e., previous fitness, nutrition, stress, weight loss), determinants of behavioural intentions to use health and fitness apps, and behavioural/personality traits (i.e., risk taking traits, healthy behaviour self-efficacy, personality traits). Participants who complete the survey will earn a $10 USD Amazon e-gift card, distributed to their participant provided email within ten days of completion.

Any games that did not utilize deposit wagers (i.e., accountability partners or no motivational booster) will not be included in the analysis. Our primary outcomes are rates of (a) initial six-month subscription and b) subscription renewal rates at six months, for the WayBetter app. User' specific metrics, 'psychological' metrics, and app engagement ('WayBetter' and 'Industry' specific) metrics of users who sign up for the 6-month subscription will be used to identify underlying homogenous subgroups of individuals using Latent Class Analysis (LCA). Next, associations between the subgroups (termed 'latent classes') to determine which users are more likely to sign-up, subscribe, and renew subscription to the WayBetter app will be examined. Linear regressions and Cox Proportional Hazard regression models to examine engagement correlates will be used. Post Hoc analysis will be used to determine between which users the statistical differences lie. The secondary objective is to describe WayBetter app engagement over 24 weeks using 'WayBetter' and 'Industry' specific engagement metrics. Descriptive statistics to summarize engagement patterns and Kaplan-Meier survival curves to illustrate time to non-usage attrition and app resumption will be used. A repeated measures ANOVA will be used to demonstrate if statistically significant differences exist between the user 'latent classes' and app engagement metrics. Regression equations and a linear probability model will be formed to predict engagement metrics using latent classes and individual-level factors (sociodemographic, previous health behaviours, determinants of behavioural intentions to use health and fitness apps, and behavioural/personality traits) as predictor variables. A sensitivity analysis will be completed to examine the effects of methods of WayBetter account creation, 1) via the WayBetter online quiz (Group A) or 2) direct download of the app on primary outcomes (Group B).