I've struggled with weight for a long time and always found myself more successful when I had an accountability buddy. I made an app that helps people create a social network around themselves for weight loss, just finished a 1.0 launch in the iOS app store. So far it integrates with just your weight from Fitbit and allows you to invite friends but thinking about adding other stuff like step count and calories.
https://apps.apple.com/us/app/supportive-social-weight-loss/id6443602611
