The Trust1Connector is a middleware that you need to install once on your device to enable SimpleSign to connect to the card reader.
The download links to the connector middleware are available in the settings menu under the tab Connector. Choose the version of the Trust1Connector that fits the OS you are using, press the link. The Trust1Connector is downloaded.
Find the package in you downloads and follow the wizard to install it.
The SimpleSign app will automatically detect the installation.