Maybe not an app, but I would suggest some PHP forum software. You can quickly spin these up on most hosting sites. Scaling it could be a problem, and you may n

Maybe not an app, but I would suggest some PHP forum software. You can quickly spin these up on most hosting sites. Scaling it could be a problem, and you may need to sustain and grow the platform with donations, or just force users to pay a set amount each month to use it. I was going to suggest AD-supported income, but I never liked that model, and most users just block ADs anyway.