PortKnock

-- Overview --
PortKnock is a port knocker for iPhone and iPad, built for network administrators, homelabbers, and anyone who keeps services hidden behind a firewall. Save your knock sequences once, then send them with a tap, a Siri request, or a Shortcut. It also runs on Apple silicon Macs.

PortKnock is NOT a hacking tool, a port scanner, or a general network scanner. It only sends knocks to servers that you own or administer.

You *must* have a port knock daemon (such as knockd) or a compatible router running on your server for this app to be useful.

-- Features --
- Siri and Shortcuts: "PortKnock _name_" or "Knock _name_ with PortKnock"
- Unlimited Knocks, each with any number of ports
- TCP or UDP per port, with optional UDP payloads
- Post-knock actions: launch an app or URL, send a webhook, or check that a TCP port opened
- IPv4 and IPv6, including hosts with multiple addresses and per-address status
- Shows your external IP address
- Configurable interpacket delay
- Backup, restore, and move devices with import preview and conflict resolution
- Migrates Knocks from PortKnock 4
- Custom symbols and colors, search, and reorder
- Dark mode
- DrayTek TOTP knocks (scan a QR code or enter your secret)
- Has no advertising

-- Use Cases --
Secure remote access: open a firewall port for SSH, VPN, or remote desktop only when you need it.
Automation: knock, confirm the port opened, then launch your SSH client or call a webhook, all from one tap or one Siri request.

This app is ideal if you're on a WiFi network but don't have a port knocker on the available computers. If you're sitting behind a NAT, your iPhone will have the same IP as any of the other computers on your network.

-- Brief Description of Port Knocking for the Layman --
Port Knocking is a technique to secure services behind a firewall until a specific knock sequence is given. This is not to be confused with port scanning (a network management tool for discovering open services on a system…