This is commonly believed, but is not actually true. Not generating revenue via the infringing activity might contribute to an argument of Fair Use, but it's not a magic wand that disappears copyright claims.

Copyright infringement is totally different from trademark infringement. Please re-read the thread.

They're not using Tinder's marks nor providing a confusingly similar brand.

Unless they copied art from Tinder, they are light years away from infringing on anyone's copyright, so I'd be even more happy to respond to those claims.