Signal is a secure messaging application that takes your privacy very seriously. By default, messages only go to your phone, but you can add other copying devices, allowing you to chat from your PC and tablet. See how you can manage devices that have access to your Signal account.
How to view your connected devices
Signal uses your phone number to identify who you are, which means you should sign up and connect using your smartphone to use the service. Once you do that, you can connect other devices, such as an iPad or a running computer MacOS, Windows ή Linux.
You can only use one "mobile device" at a time with Signal, but you can connect up to five other devices, such as tablets or laptops. This means that you can only connect one main iPhone or Android smartphone in your account at any time. If you want to switch from Android to iPhone or vice versa, you will need to sign up again.
To view existing connected devices or to add more, open Signal on your main smartphone and tap its icon Profile you in the upper left corner of the screen. Click on "Linked Devices" in the menu shows up to see the other devices you have added. Click the "Link New Device" button to add another device using one QR code.
Disable connected devices in Signal
Your main Signal device - the main smartphone you - can used to disconnect any connected devices. To do this, reveal your connected devices by clicking on your profile icon in the upper left corner application.
Then select "Linked Devices" from the menu shows up.
To disconnect a device, swipe left and press the “Unlink” button that appears. You will be asked to confirm your decision at the bottom of the screen.
If you try to send messages using a disconnected device, you will see one warning inform you that you must reconnect your device to resume normal use.
Disconnecting a device will also delete any chat history on that device, as conversations are not transferred to new devices for safety reasons.
Source of information: howtogeek.com