To set up Signal on your phone, you have to install the app from your device’s App Market. Make sure that your device is updated to the latest version. Open the app and follow the instructions to register. If you wish to use the Signal app desktop version it has to be linked to your phone. Signal can’t be used without a phone number. After installing the app on your mobile device and completing the registration, make sure your computer supports Signal Desktop. You need to have Windows 7 or above, macOS 10.10 or above, or Linux 64-bit supporting APT. Then, download the Signal Desktop on your computer and link it to the mobile device, open the Signal app on your phone, navigate to Signal Settings, then to Linked Devices. Click Link New Device for iOS or the plus icon for Android. Using. Phone, scan the QR code that appears on your computer. Name the linked device and click “Finish”.