Dozy Activator is a program that modifies the Tomb Raider: The Last Revelation's SCRIPT.DAT file to enable the dozy cheat. It was made with the intention of being very simple and easy to use.
Dozy is the name of the cheat that gives Lara all the items and activates the flight mode. You can activate this cheat by holding the D O Z Y keys (make sure that your keyboard layout doesn't use those keys). Deactivate the flight mode by pressing Walk.
After opening it, click Choose file and select the SCRIPT.DAT file inside TR4's game folder. Now you can click Toggle to toggle the cheat on and off. Leaving the cheat enabled should have no effect when playing the game.
This program was written in the C# programming language using Visual Studio 2015. I made use of the incredible documentation available at http://opentomb.earvillage.net/OpenTomb/doc/trosettastone.html .