FFVII: REBIRTH is a free modification for the PSX classic, that seeks to rebalance the game, improve the difficulty level, add new spells and mechanics, and in essence make the game a more engaging, tactical experience. REBIRTH is unlike other modifications of its kind, insofar as it is for the *PSOne* version of the game, though a PC port will follow.
This video is also available on YouTube, with annotations:
That video was quite a bit more helpful than the images. I followed it a lot better.