Sketch Mirror - Preview your iOS designs directly on your devices
Diagrams for Mac - A diagram editor for visualizing structures and processes
Flowkit - Sketch library for user flows/content maps/annotations
Diagrammm - Fundamentals on data visualization
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.
Screenshot Flow - Super fast app diagrams to communicate design