The Lounge is rated Safe For Work. If you're about to post something inappropriate for a shared office environment, then don't post it. No ads, no abuse, and no programming questions. Trolling, (political, climate, religious or whatever) will result in your account being removed.
You download the software (sorry, all Mac software) and use it. And you pay for it whenever. You must pay for it, but when you pay for it you don't actually get anything (e.g., a product key). They are using the honor system. Quite refreshing to see somebody bold enough to take this approach.
I just tried one of the products. When you quit the app, it asks you if you bought it. You just confirm and that's it.