Glyph is a tool for generating seamlessly looping GIFs and cinemagraphs from videos. Download Glyph for Mac. See some examples.
What Glyph can do:
Automatic Loop Detection: Automatically detect perfect loops that occur in a video
Seamless looping for non-looping clips: Create the appearance of seamless motion in a non-looping clip through time-symmetrization and fading effects
Masking: Still some regions of movement in a clip to highlight others
Cinemagraphs and "Moment Imagery": Imbue a still frame with just enough dynamism to hold our eyes and pique our interest