Trainer
From Sega Retro
Trainers are programs made to modify behaviour of a computer game, usually using addresses and values, in order to allow cheating.
In the 1980s and 1990s, trainers were generally integrated straight into the actual game by cracking groups. When the game was first started, the trainer loaded first, asking the player if he/she wished to cheat. Then the code would proceed to the actual game. In the cracker group release lists and intros, trained games were marked with one or more plus signs after them, one for each option in the trainer, for example: "the Mega Krew presents: Ms. Astro Chicken++". Modern trainers append their titles with a single + and a number, as many have several functions. The number used represents the number of modifications the trainer has available, eg. 'infinite cash' or 'instant research'. For example: "Final Fantasy VII - Ultima Edition +50 Trainer".
Modern trainers also come as separately downloadable programs; instead of modifying the game's programming directly, values stored in memory are changed.