Currently trying to get the pieces together to do this. Where did you find the download to Robertfs app? The link to the Google store seems to be dead

 

Try GEMS ECU Utility for Land Rover on Google Play. I use GEMS Lite.

The system will re-adapt by driving, so resetting is not absolutely necessary, but the truck might run a little rough until the trims are adapted to the new values. Resetting simply goes to factory default trims (zero level), then drive cycles adapt to present conditions. You can monitor this with your real-time scanner. Record short and long term fuel trims at the beginning and monitor them over time to see how they change.