Support

What do I need to use SIM Cat?

A server that you or someone you trust runs, an Android phone with your SIM cards running the agent, and a login for that server. SIM Cat has no servers of its own: OKPATH does not provide servers, accounts, phone numbers or SIM plans. How it fits together explains the parts and the ports.

I can’t sign in. What do the messages mean?

On the sign-in screen, enter your server as a host name (sim.example.com) or with a port (sim.example.com:30443); without a port SIM Cat uses 30443. Then your login and password. SIM Cat connects over HTTPS only.

• “Wrong login or password.” The server refused the login. Ask your administrator to check the account or reset the password.
• “Can’t find … Check the address.” The host name does not exist. Check it for typos.
• “Can’t reach … Check the address, your connection and that the server is running.” Nothing answered. Check that your iPhone is online, that the server is running and that TCP 30443 (or the port you entered) is open to the internet.
• “… doesn’t have a valid HTTPS certificate for this address.” The server’s certificate must come from a public certificate authority, for example Let’s Encrypt, and must be valid for the host name you typed. SIM Cat refuses a connection otherwise.
• “… answered, but it doesn’t look like a SIM Cat server.” The address leads to something else, such as a web server. Check the host name and the port.
• “Too many attempts.” The server is limiting logins. Wait the time shown and try again.
• “Your session ended. Sign in again.” The server ended the session, for example because the installation was revoked or the account was changed. Sign in again.

If it still fails, export the log (below) and send it to support.

Incoming calls don’t ring when the app is closed.

Incoming calls reach a closed app through Apple push notifications, which your server sends. In SIM Cat, open Settings and look at This iPhone:

• Push: Registered means your server has this iPhone’s push tokens. If it says “Background calls unavailable”, the server cannot send pushes to this build; ask your administrator. Calls still ring while the app is open.
• Calls: Ready is what you see while the app is open. In the background it reads “Paused in background”, which is normal: the push wakes the app.
• Message alerts need notifications to be allowed for SIM Cat in iOS Settings › Notifications. Incoming calls use the iOS call screen and follow your Focus settings.

Also check that the Android phone is online and that your line shows as available in SIM Cat’s Settings under Lines.

There is no sound, or the call says it has no audio.

SIM Cat shows “No call audio yet” when no audio arrives within a few seconds, and “This network blocks call audio” when it still does not after about twelve. Call audio travels over UDP; some networks block it.

• In Settings, under Calls, set Relay Call Audio to Always. The call then goes through your server’s relay, which works where UDP does not. Under This iPhone, Call relay must read “Available”; “Not offered” means your server has no relay, and your administrator needs to set one up.
• Try another network, or ask your administrator whether UDP ports 10000–10031 are open on the server.
• Check microphone access: SIM Cat shows a Microphone line in Settings while access is off or not yet allowed. Turn it on in iOS Settings › SIM Cat.

How do I send a log?

In SIM Cat, open Settings and tap Export Log, then choose where to send the file in the iOS share sheet. It holds the app’s technical events from the current run: app and iOS versions, times, sign-in and sync steps, call setup and audio statistics, error codes, and network addresses such as your server’s host name and IP address. The app removes passwords, tokens and message text and masks phone numbers to their last four digits, but the redaction is automatic, so read the file before you send it. Nothing is uploaded unless you share it.

How do I sign out or use another server?

Open Settings and tap Sign Out under Account, which also shows the server you are signed in to. SIM Cat tells the server to stop ringing this iPhone, ends any call, and clears its cached lines, history and messages. The sign-in screen then starts with your last server filled in, and you can enter a different one. You can also remove another iPhone you signed in with: Settings › Other Installations › Revoke.

Can I place emergency calls?

No. SIM Cat cannot place emergency calls, and it refuses short numbers such as 911 and 112 and tells you to use your iPhone’s own dialer.

What is the demo server?

OKPATH runs a demo server for Apple’s App Review and for demonstrations. It has simulated phone lines and is not connected to any phone network, so no real call or text is placed on it. It is not a service for everyday use. The Privacy Policy says what it receives.

How do I remove the app and its data?

Sign out first (Settings › Account › Sign Out): it revokes this iPhone on the server and clears the cached lines, call history and messages. Then delete the app: touch and hold the SIM Cat icon, tap Remove App, then Delete App. That removes everything else the app stored on your iPhone. Accounts and server-side records belong to whoever runs your server; ask them to delete them. OKPATH holds only the TestFlight information Apple shares and your support emails; to ask us to delete those, email privacy@okpath.com.

How do I get new builds or leave the beta?

TestFlight installs new builds when you turn on automatic updates for SIM Cat in TestFlight, or when you tap Update there. To stop testing, open TestFlight, choose SIM Cat and tap Stop Testing.