There are currently at least four versions (v0.1-0.4).
PikaSav can modify:
1. The player name 2. Play time 3. Rival name 4. Game Corner coins
5. Party Pokémon data. For Generation I, glitch Pokémon can be input in the format ~[index number], e.g. ~242 is ゥ (F2) (Red/Blue) or ゥ ゥェ ゥ ▷ (F2) (Yellow). 6. PC Pokémon data. 7. Bag items. 8. PC items. 9. Pokédex data.