Free your phone from spam calls 🤖

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Castle blocks neighbor spoofing robocalls instantly, simply enter the first 6 digits of the phone number and it's done, no need to access your contacts.

At best, these calls annoy. At worst, they defraud to the tune of $20 billion a year just in the us. We're here to use an algorithmic approach to combat this epidemic.




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Amrith Shanbhag@amrith · Community at Product Hunt & Feathrd
How does this work @nicholassheriff?
Nicholas SheriffMakerPro@nicholassheriff · Founder, Sheriff Ventures
@amrith Hi Amrith, Castle is designed intelligently with a more algorithmic approach to number blocking due to the way numbers actually are generated and what those numbers actually mean....We arm users with the ability to dynamically block every single number that a robocaller would generate in the future instantly and that single block can stop hundreds of thousands of numbers, jright now the provided solution wants you to manually enter thousands of numbers a day to block. Unfortunately the fastest growing robocall technique ( growing because it’s more effective ) is NPA-NXX Spoofing Also known as neighbor spoofing. Growing by over 1,000% and represents over 60% of all robocalls and 80% of all new robocall growth. NPA stands for the first 3 numbers of a phone number, representing the state and geographical region or origin, and NXX the next 3 represents the city and phone carrier. The unique Id of the phone number is actually the last 4 digits and that is not spoofed by a robocalled unless they have hijacked your cell num. So unlike most robocalling apps, that list they keep telling you that’s updating even if it was possible to be collected right now would be outdated within 5 minutes from now. We don’t ask for your address book because ( we feel it’s wrong ) and we don’t need It out tech runs 100% on your device nothing is shared in the cloud as no servers are involved. I have Castle installed on my phone and it's so far blocked 99% of all my robocalls....I was use to getting 10-25 a day.
Kaitlyn Hanrahan@kaitlynhanrahan · Simply.Digital
@nicholassheriff amazing! Can't wait to try it! This year I've started getting multiple spam calls a day.
Cam BurleyPro@codecamcode
This seems really cool. I get 20 calls a day and it drives me crazy. How does it actually work? What are my steps? and how does it avoid future robocalls w/o blocking numbers I want to receive calls from?
Nicholas SheriffMakerPro@nicholassheriff · Founder, Sheriff Ventures
@codecamcode @codecamcode Thanks Cam, and I'e been there and it's only going to get worse without some kind of protection that's more algorithmic for the users end that's the only solution that would make robocalling co scared and work effectively. Think of our solution as a beta Google and think of every single solution from anywhere as Yahoo, one of which works toward combating the future of robocalling because they will only embrace tech a lot more aggressively and we’ll be right there with them. This is how it works: You're typing in the first 6 digits of the number which includes your NPA & NXX number and instantly that neighbor spoofing technique used with those digits will automatically be detected and blocked, from any range. Currently the drawback of not asking for your address book is that we don't know the numbers you need to leave open, but the block isn't a complete sends the caller to your voicemail but we're working on an update for a dynamic whitelist, with everything still living on your device and doing the blocking with your own system nothing at all touches a server. We also will allow you to input numbers to white list manually in the next update just in case you’ve noticed the system is blocking your contacts. We have a lot planned, with machine learning as well all run on the device nothing runs on our server with Castle. ( for privacy reasons but this also means everything is instant/no latency and saves us $ over time ). We're planning an update to include this in the coming weeks.
Cam BurleyPro@codecamcode
@nicholassheriff thanks for the reply. So my prob is that, the robocalls have gotten much more clever. My phone number starts (202) 607 — callers know that and they’ve started using numbers with this prefix. Problem is, not only is that my number’s prefix but also my moms, brothers, and other ppl from home. Without much manual work, I’d like to continue getting calls from people I want to receive them from and exclude those numbers that are foreign to me
Nicholas SheriffMakerPro@nicholassheriff · Founder, Sheriff Ventures
@codecamcode I hear you Cam and we are literally a few weeks away you'll be able to add your address book onto the app ( their isn't a server that touches your address book ) it lives inside of your device and the app just launches that list along with the others so it will be pretty seamless. as in two taps and those numbers won't be blocked. So stay tuned!
Igor Escobar@igorescobar · Founder of / Engineer
Congrats @nicholassheriff! Looking good!
Ayush Chandra@ayush_chandra · Research Intern & Tech Evangelist
Great job!! 😊 How’s it different to Truecaller? Does it support it to India?
Ramy Al-Kadhi@ramy_alkadhi · Creating mindful technology.
Great product.