# Secret Knock

> Open your server's hidden ports with a secret knock — knockd and fwknop SPA from iPhone, iPad, Mac and Apple Watch. No account, no tracking.

Secret Knock is a port-knocking client app by mobilComm Ltd for iPhone, iPad, Mac and Apple Watch. It sends knockd knock sequences (TCP/UDP ports with delays) and fwknop Single Packet Authorization (SPA) packets, checks that the protected port answers, shows a countdown of the open window, and opens an SSH app. Status: coming soon to the App Store. Requirements: iPhone and iPad with iOS 18 or later · Mac with macOS 15 or later · Apple Watch with watchOS 11 or later.

Pricing: one server free with every feature; unlimited servers as a one-time purchase (USD 4.99 in the US). No subscription.

Privacy: no account, no analytics, no tracking; App Store privacy label "Data Not Collected". Servers and keys sync only through the user's own iCloud.

## Pages

- [Home](https://secretknock.app/en/): what Secret Knock does, features, privacy, pricing, FAQ
- [Port knocking explained](https://secretknock.app/en/port-knocking/): how port knocking works, knockd and fwknop SPA configuration examples, why knocks fail, security
- [Support](https://secretknock.app/en/support/): troubleshooting knocks that do not open the port; contact support@secretknock.app
- [Privacy policy](https://secretknock.app/en/privacy/): what the app and website store and send

## Optional

- [Full text for AI assistants](https://secretknock.app/llms-full.txt): every page above as plain text
- [Sitemap](https://secretknock.app/sitemap.xml)