Connect a device - Kickoff Companion

Connect a phone or tablet

Any device on the same Wi-Fi opens the app in its browser. Nothing to install: scan the code with the camera, or type the address.

Point the camera at the code and tap the link it shows. Some Android phones cannot use names that end in .local; the number address always works.

iPhone and iPad (Safari): the Share button, then Add to Home Screen.
Android (Chrome): the menu, then Add to Home screen or Install app.
A computer: bookmark it, or in Chrome and Edge use Install in the address bar.

After that it opens with one tap, full screen. The app keeps the screen awake during games once you tap anywhere on it.

iPhone and iPad

Tap Download certificate above. Safari asks to allow a configuration profile. Tap Allow, then Close.
Open Settings. Tap Profile Downloaded near the top (or General, then VPN & Device Management). Tap Install, enter your passcode, tap Install again.
Open Settings, General, About. Scroll to the bottom and tap Certificate Trust Settings. Turn on the certificate named above and confirm.
Come back here and open the app.

Android

Tap Download certificate. The file lands in Downloads.
Open Settings and search for CA certificate. It usually sits under Security, Encryption & credentials, Install a certificate. Choose CA certificate, tap Install anyway, and pick the downloaded file.
Android shows a "network may be monitored" notice while a personal certificate is installed. That is expected.
Then open the app from Chrome.

Windows

Click Download certificate, then open the downloaded file and click Install Certificate.
Choose Current User, then Place all certificates in the following store, Browse, and pick Trusted Root Certification Authorities. Finish and accept the security warning.
Or run this in PowerShell after downloading: Import-Certificate -FilePath "$env:USERPROFILE\Downloads\kickoff-companion-ca.crt" -CertStoreLocation Cert:\CurrentUser\Root
Chrome and Edge trust it right away. Firefox keeps its own list; see the Firefox section.

Mac

Click Download certificate and open the file. Keychain Access adds it to the login keychain.
In Keychain Access, double-click the certificate named above, expand Trust, and set When using this certificate to Always Trust. Close the window and enter your password.

Linux, the Steam Deck included

Firefox (the Steam Deck's browser and most others'): follow the Firefox section below. Firefox keeps its own list, so this works without admin rights.
Chrome, Chromium or Edge keep their own list on Linux too. Open chrome://certificate-manager (older versions: Settings, Privacy and security, Security, Manage certificates), go to the certificates you installed yourself, choose the trusted authorities list, click Import, pick the downloaded file, and allow it to identify websites.
For the whole system (command-line tools and other apps; needs admin rights, so not on the Steam Deck's read-only system). Debian or Ubuntu: sudo cp ~/Downloads/kickoff-companion-ca.crt /usr/local/share/ca-certificates/ && sudo update-ca-certificates. Fedora or Arch: sudo trust anchor --store ~/Downloads/kickoff-companion-ca.crt.

Firefox on any computer

Click Download certificate in Firefox. A dialog offers to trust the authority. Tick Trust this CA to identify websites and click OK.
On Windows you can instead type about:config in the address bar, search for security.enterprise_roots.enabled, and set it to true so Firefox uses the Windows list.