The Wii's sensor bar system assumes you have a specific TV size, so using it on modern big TVs will result in the pointer not appearing in the right spot (different from where you're actually pointing the Wii Remote). This homebrew app would help with that by installing a cIOS that handles the sensor bar pointing system and allows for calibration.
This would work in a similar way to the pointer calibration feature in Twilight Princess, but it would be a system-wide change. You would choose Above TV or Below TV, set the width and position of the sensor bar, and specify the vertical distance (in centimeters or inches with decimals) between the sensor bar and the actual screen. It would use the Wii's aspect ratio setting to decide if it should use 4:3 or 16:9, and it would use this data to put the pointer in a more accurate spot.