Facebook has been paying teens $20 per month for all of their data. The Social Media Company has been secretly paying people for the purpose of installing a "research VPN".
The research VPN basically allowed the company to look in on a person's phone and web activity. This app seems to be similar to Onavo - Facebook's VPN. However, this later got banned. Onavo could track everything including the apps you use, the web traffic and lastly your data too.
Onavo was banned by Apple and after that Facebook now seems to have turned to this app. It is since the year 2016, that users between the ages 13-35 are being paid around $20 per month + referral fees for selling their data by installing the app.