Frontier runs on your own computer, but that doesn't mean you have to be sitting at it. Remote Access, in the account menu behind your avatar, shows a QR code. Scan it with the Frontier app on your phone, and the same install opens there. Not a copy, not a cut-down version: the same workspaces, the same threads, the same agents still running on the machine at home.
It is the ordinary use that makes it worth setting up. An Agent finishes something while you're out, and you can read what it did, answer the one question it got stuck on, and let it carry on, from the kitchen or the train.
Pairing ends at your computer. The app shows a six-digit code, and your computer asks whether to allow the phone, showing the same code. Allow it only when the two match. From then on the phone proves who it is on every connection, so nothing else on your network can open your Frontier, even if it knows the address. Remote Access lists every phone you've paired, and Revoke cuts one off straight away.
Rather open it in a phone's browser, without the app? Turn on "Allow browsers on this network without a paired device" under Settings → Remote Access. A browser shows a one-time warning the first time, since the certificate comes from your own install rather than a public authority. "Trust this machine", and the second QR code that installs the certificate on your phone, make every later visit silent.
If the machine has more than one network connection, pick the address your phone actually shares with it from the dropdown. Pairing always happens here, on your own network. After that, the phone can reach you from anywhere: see Using Frontier away from home. Either way, your work stays on your own machine, as it always does.