LG has not approved the HDHomeRun app for any TV model outside of the US.
LG has not approved the HDHomeRun app for release on newer TVs in the US.
The HDHomeRun will attempt to automatically scan for channels the first time it is connected to power, and will occasionally do a background scan every few days, but you may still need to run an initial channel scan.
This is unfortunately a known limitation due to how the LG video player works, where seeking does not work if the player does not know when the video ends (which doesn't exist on a live channel). Seeking will work on recordings.