You Need A Wiki - Create a wiki with Google Docs
Watermark.ink - Online Photo Watermarker
Stack Overflow Documentation - A crowdsourced developer documentation
AG Audio Watermark Generator - AG Audio Watermark generator is a little app for both mac and pc that will help you to add an audio watermark to your original track in a fast & easy.
Docusaurus - Easy to maintain open source documentation websites
textmark - Protect your content with an invisible, trackable watermark.