Photomosh - Turn anything into a vaporwave
Sketch Mirror - Preview your iOS designs directly on your devices
MVGEN - Make your own music videos with audio, gifs, and special effects
Crystal: Sketch Mirror for Android - Crystal: Sketch Mirror for Android is an application that is designed for viewing your sketch designs in real-time, navigate prototypes and download content related to the sketches for offline viewing.
HearSeeParty - Combine Gifs with with music using tags
Flowkit - Sketch library for user flows/content maps/annotations