Yes, I do, most projects are (currently) not open-sourced, but Aureal is:

• Haveyoubeenhere: https://haveyoubeenhere.com
• Dapplr: https://dapplr.in/ ​
• Aureal: https://aureal.one - https://github.com/thewall4095/aureal_mobile_frontend

For Flutter you also don't "need" it, but I do feel most developers (definitely if you are handling different type of social logins) will want to understand how to get everything verified on the back-end too! 😁