Hey Product Hunt 👋 I'm Ammon. I built NumBan because I got tired of dozens of scam calls per week that leave me voicemails for scams. I can't answer unknown numbers any more (and they automatically go to voicemail now, too). Blocking doesn't work because caller ID is fake. But every scam voicemail has one thing that isn't fake: the number they want you to call back. It has to ring a real phone somewhere, which means some carrier is hosting it. So NumBan goes after that number. You share the voicemail from your Phone app, and NumBan: - pulls the callback number out of the audio - figures out which carrier or toll-free provider hosts it - sends them an abuse report once enough people have reported the same number - pings the number every week until it's dead and notifies you of your good work Dead numbers count as kills and go on a leaderboard. The leaderboard counts kills, not reports, so you can't farm it by sharing the same voicemail fifty times. The fun part of building this was finding out how hard it is to learn who owns a phone number. Toll-free numbers, which is what most scammers leave, live in a registry you can't just query with an API key. That turned into a long detour through RespOrgs, porting databases, and a legacy phone systems. Right now reporting is free for the first three, then I have to cover costs so I charge the App Store minimum $0.99 per month. I'd love to hear two things: does the leaderboard make you more likely to report, and what's the most ridiculous scam voicemail you've ever gotten?

NumBan

Report voicemail callback numbers, not spoofed caller ID.

Report voicemail callback numbers, not spoofed caller ID.