Radio Silence

Most people who abandon an outbound firewall do it for the same reason: the dialogs. Radio Silence takes the opposite position. You open it, tick the apps that should never reach the network, and then you never hear from it again. There is no rule language, no profiles, no learning period, and no window that needs to stay open.

That makes it the right tool for a specific job: you have three or four apps whose phoning home you want to end, and you would like that finished in two minutes. A creative suite's telemetry, an app whose update nagging you are done with, something you would rather kept its licence checks to itself. The Network Monitor is there if you want to watch what is currently talking, but the app's whole personality is that you are not asked to care.

Nine dollars, once, with a month to change your mind. For that price, arguing about whether version 4 will cost extra feels like the wrong argument.

It is the wrong buy if you want to allow an app's updater while blocking its analytics, or to write rules per domain and port. That is Little Snitch's work, and it costs several times as much for exactly that reason. If you want the prompting model without paying, LuLu is free.