Quad9 Connect is an Android application for Android 9 and later, which creates a secure tunnel between the device and Quad9 for sending DNS queries via DNS over TLS, and also provides additional features like a query log, one-click service switching, and the ability to report false positives.
Quad9 Connect is not a VPN, but uses the VPN functionality of the device to accomplish encrypted DNS and the features associated with the application. When Quad9 Connect is enabled, it's not possible to use another VPN connection on the device; if you want the benefit of encrypted DNS, but also want to run a separate VPN connection, you may consider setting up Quad9 in the Private DNS Android feature instead of Quad9 Connect.
Step 1 - Install
Install the latest version of Quad9 Connect from the Google Play store: Quad9 Connect
Step 2 - Activate
To activate the Quad9 service, launch the Quad9 Connect app and simply select the Play Button icon.
Once the app is activated, you will see the play button switch to a top button and a temporary message stating "Connected to Quad9!"
Step 3 (Optional) - Settings
To configure Quad9 Connect to use non-default settings, select the collapsed menu icon followed by selecting Settings.
The Quad9 Connect app allows you to configure which Quad9 services you wish to use and customize the apps behavior on your device.