Materialize is a stand alone tool for creating materials for use in games from images. You can create an entire material from a single image or import the textures you have and generate the textures you need.
WOLF RPG Editor is a game construction tool that can create complex role playing games. It is often regarded as being aimed at advanced users, so keep this in mind if you intend to use it. It was developed by SmokingWOLF (SilverSecond) in Japan.