Freesound - The Freesound Project is a collaborative database of Creative Commons licensed sounds.
UX Flow Wireframe Prototyping System - Create beautiful user flows prototypes for your next project
Sample Focus - The easiest way to find the perfect audio sample
draw.io - Online diagramming application
Moody sampler - A cloud connected audio sampler, including 1000+ instruments
yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.