The last option is whether or not to open the finished animated gif in the Fractal Movie Viewer (unless you terminate the creation of the movie before the last frame is reached). This viewer can play back the fractal movie (animated gif). Note that the Fractal Movie Viewer has its own controls for how often the animation is played and for the frame rate. The options that you set when saving the animated gif will apply only to the saved file (when viewed in a web browser, for example).
Important Note: Saving frames or the movie as an animated requires that the file FreeImage.dll exist either in the same folder as the IFS Construction Kit program or in the windows/system folder. FreeImage.dll is included in the zip file for IFS Construction Kit that can be downloaded from http://ecademy.agnesscott.edu/~lriddle/ifskit.