Yes, I've been using Zwerl app since November 2018 and I personally earned from the platform. They pay good enough. The app has been around since 2 years ago and have helped many Experts who give great answers to each questions. I got paid twice since November, they pay once a month.
The Zwerl app actually have strict rules and you really need to abide with their rules so that you won't be suspended or banned from the program. Many bad reviews are given to the app due to the fact that they really suspended many accounts. Some claims they haven't committed any violations. Some claims that Zwerl has lift up suspension of their account after series of communication with the Support team.
My take is, this app is 100% Legit and you just need to follow the rules and provide great and helpful answers.
Thank you and have a wonderful day.