|Google Play:||Check if it's there|
This applications allows you to check the Treble GSI requirements and determine the correct GSI type for your device.
You can download GSIs from all over the internet. Check the XDA Forums (not affiliated) for some easy tutorials.
NonFreeDep: The application depends on a non-free application (usually Google Services) – i.e. it requires it to be installed on the device, but does not include it.
NonFreeNet: This application promotes or entirely depends a non-Free network service.