Grand Theft Auto San Andreas
GTA IV Mod Installer + MI Packager v0.2
Here is the GTA IV - Mod Installer and MI Packager V0.2, which does exactly what it sounds like it installs modifications to GTA IV. This also has the ability to create modifcation installers, so
that you can make installing your modification a lot more easier. Although you can't install modifications for files that require you to manually install items to .img files as of yet with this program.